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Nature Communications volume 16, Article number: 4827 (2025)
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Stacking two non-polar materials with different inversion- and rotational-symmetries shows unique nonlinear photovoltaic properties, with potential applications such as in next generation solar-cells. These nonlinear photocurrent properties could be further extended with broken time reversal symmetry present in magnetic materials, however, the combination of time reversal and rotation symmetry breaking has not been fully explored. Herein, we investigate the nonlinear photovoltaic responses in van der Waals heterostructure compromising of monolayer semiconductor and layered magnetic material, MoS2/CrPS4; a system with broken P– and T-symmetry. We clearly observe the finite spontaneous photocurrent as shift current at the interface of the MoS2/CrPS4 heterostructure. Moreover, we demonstrate that the spontaneous photocurrent drastically changes according to the magnetic phases of CrPS4. The magnetic phase dependent spontaneous nonlinear photocurrent provides a platform for studying nonlinear photoresponses in systems with broken P– and T-symmetry, and the potential development of magnetic controllable photovoltaic devices.
Recently, the introduction of shift current concepts from topological physics drastically extend the possibilities for photovoltaic devices because of their unconventional spontaneous photocurrent properties1,2,3,4. The shift current as one of the bulk photovoltaic effects are the most promising photovoltaic responses to be able to overcome the Shockley–Queisser limit in the conventional p-n junction photovoltaic devices5,6,7,8. These anomalous photovoltaic responses including extremely large open-circuit voltage, not limited by band-gap energy, and robust photocurrent to defects and impurities of materials, have been observed in the polar bulk materials9,10,11,12,13. The shift current could be explained as topological photocurrent depending on Berry connection, which is a vector in real space indicating the information of center-of gravity position of electrons14,15. In the crystal with broken spatial inversion (P-) symmetry, the imbalance electron “shift” due to optical interband transitions before and after photoexcitation is occurred, which then generates the spontaneous photocurrent under zero-bias conditions as shift current. In addition to the shift current, the nonlinear topological photoresponses also induce the injection current, which is caused by difference of group velocity and imbalance photoexcitation with circular polarized light in k-space16,17,18. Since the shift current and injection current are induced by the linear- and circular-photogalvanic effects (LPGE and CPGE) of linearly and circularly polarized light, respectively, their effects are generally observed separately. However, in time-reversal (T-) symmetry broken crystals such as some layered magnetic materials, each spin band is lifted by spin polarization and shows an imbalanced band structure in momentum space. The electron is photoexcited unevenly in terms of momentum, and the group velocity of the electron is not perfectly canceled, which would induce a linear injection current in systems with broken T-symmetry19,20,21,22. The shift current is also induced by the CPGE after the magnetic transition. These magnetic PGEs have odd parity under magnetization changes; thus, they are not observed in nonmagnetic materials where T-symmetry is preserved23.
The emerging two-dimensional (2D) materials, including semiconducting transition metal dichalcogenides have opened the new research fields in the fundamental science and potential applications in various electronic and optical applications24,25,26. The artificial van der Waals (vdW) heterostructures fabricated by stacking 2D materials lead to induce the emerging periodicity of crystal structures such as moiré superlattice27,28,29,30,31,32 and provide us the new pathways to control the P-symmetry at their heterointerfaces. Recently, it has been reported the nonlinear photocurrent arising from shift current in the artificially P-symmetry breaking vdW heterointerface by stacking three-fold symmetry MoS2 and two-fold symmetry black phosphrous33. Moreover, the artificial symmetry breaking would extend the exploration for high efficiency shift current photovoltaic devices34,35,36, however, no promising candidates have been shown37. Accordingly, it is crucial to experimentally investigate the shift current and injection current depending on Berry connection and Berry curvature in the novel interface of vdW heterostructure with the systems with broken P– and T-symmetry. The understanding of nonlinear photocurrent responses in the vdW heterostructure with the system with broken P– and T-symmetry would provide the ground breaking importance for fundamental physics and applications for emerging photovoltaics.
In this study, we demonstrated the nonlinear photoresponses in monolayer semiconductor and layered magnetic materials vdW heterostructure with the system with broken P– and T-symmetry. The shift current along the direction of parallel to P-symmetry broken axis at the interface of MoS2/CrPS4 vdW heterostructure has been experimentally observed above 40 K. Moreover, we demonstrate the switchable spontaneous photocurrent arising from the magnetic phase transition of CrPS4 in vdW heterostructure depending on the temperature and external magnetic fields. The detail physical mechanism of anomalous spontaneous photocurrents in the vdW heterostructure with the system with broken P– and T-symmetry will be discussed.
Figure 1a shows a schematic of photocurrent measurement of monolayer (1L)-MoS2 and multi-layers CrPS4 vdW heterostructure device. The rotational and P-symmetry by stacking of three-fold symmetry MoS2 and two-fold symmetry CrPS4 are diminished, and reduced at their interface38,39,40, and only one-mirror plane is maintained at the vdW interface, as shown in the inset of Fig. 1a. The (x, y, z) axes are defined for the crystal structure as shown in the inset of Fig. 1a. Figure 1b shows the optical image of monolayer MoS2 and multi-layers CrPS4 vdW heterostructure device. The monolayer MoS2 and multi-layers CrPS4 were mechanically exfoliated from bulk single crystals, respectively, and then the monolayer MoS2 was stacked on multi-layers CrPS4 by dry transfer method (see the “Methods” section). The twist-angle between MoS2 and CrPS4 was controlled to match each mirror planes with judging from each characteristic cleaved edge angle of 67.5° and 60° for multi-layers CrPS4 and monolayer MoS2, respectively41,42,43. The heterostructure fabrication was confirmed from photoluminescence spectrum as shown in Fig. 1c.
a Schematic of photocurrent measurement of 1L-MoS2/CrPS4 vdW heterostructure device. The inset shows schematic of in-plane crystal structure of 1L-MoS2/CrPS4 vdW heterostructure. The green and red dotted lines show the axis of inversion symmetry MoS2 and CrPS4, respectively. In the heterointerface, the inversion symmetry is reduced to maintain in only one mirror plane and rotational symmetry is canceled. Consequently, the spontaneous polarization indicated by the red arrows with broken P-symmetry are induced, according to the overlapped mirror plane. b Optical image of 1L-MoS2/CrPS4 vdW heterostructure device. The scale bar of 20 μm is shown in the images. The 1L-MoS2 was stacked on multi-layer CrPS4, and four-electrodes were fabricated along to parallel and perpendicular to expected polarization direction. c Photoluminescence (PL) spectrum of 1L-MoS2/CrPS4 vdW heterostructure. The PL peaks at 1.92, and 1.38 eV correspond to the emissions from 1L-MoS2, and CrPS4, respectively. d I–V curve of 1L-MoS2/CrPS4 vdW heterostructure device under dark and laser illumination of 532 nm conditions. e I–V curve of 1L-WSe2/CrPS4 vdW heterostructure device under dark and laser illumination of 532 nm conditions.
Figure 1d shows the current–voltage (I–V) characteristics measured along the x-axis of MoS2/CrPS4 vdW heterostructure device, under dark (black) and illumination of linearly polarized light of 532 nm (red) at room temperature. The I‒V characteristics under dark conditions show simple linear behavior in the current when the applied bias voltage is not zero. The significant finite value of spontaneous photocurrent at zero-bias voltage is clearly observed under laser illumination, which is in contrast to no spontaneous photocurrent, i.e. the zero-current at zero-bias voltage under dark condition. Moreover, the spontaneous photocurrent under light illumination is also observed in the WSe2/CrPS4 vdW heterostructure based on different monolayer semiconductor, as shown in Fig. 1e (see details in Fig. S1). Spontaneous photovoltaic effects were not observed in the devices with only the MoS2 monolayer or bulk CrPS4 (see Figs. S2 and S3). These results strongly imply that the experimentally observed spontaneous photocurrent is a universal behavior in the monolayer semiconductor transition metal dichalocodenide/CrPS4 vdW heterostructure device.
Figure 2a shows the optical image of MoS2/CrPS4 vdW heterostructure device with four electrodes (E1–E4) to investigate the direction of nonlinear spontaneous photocurrent, where the four electrodes indicated by red dashed lines are fabricated in the center of MoS2/CrPS4 heterostructure region. The photocurrent measurements using E1 and E2 (E3 and E4) correspond to photocurrent generation along the x– and y-axes, respectively. It has been well known that the shift current strongly depends on spontaneous polarization direction33,44. The significant spontaneous photocurrent at zero-bias voltage is clearly observed along to the x-axis and mirror plane, while no spontaneous photocurrent is observed along to the y-axis even under the same photoexcitation conditions, as shown in Fig. 2b.
a Optical image of 1L-MoS2/CrPS4 vdW heterostructure with four electrodes configurations. The electrodes are highlighted in red dotted lines, and each electrode is assigned as E1–E4 to clarify measurement direction. The scale bar of 5 μm is shown in the images. Hereinafter, measurement results without annotations indicate the results between the E1 and E2 along to predicted polarization direction. b I–V characteristics of 1L-MoS2/CrPS4 vdW heterostructure under the laser illumination of 532 nm, which were measured by different current detection configurations with parallel (E1 and E2) and perpendicular (E3-E4) to expected polarization. c I–V characteristics of 1L-MoS2/CrPS4 vdW heterostructure with various excitation powers. d Excitation laser power dependence of spontaneous photocurrent of 1L-MoS2/CrPS4 vdW heterostructure. In the low power region, the spontaneous photocurrent is proportional to the laser power, whereas the square-root dependence of the photocurrent is observed in the high power region. e Photocurrent mapping measured between the E1 and E2 electrodes, indicated by the dotted lines. f Polar plot of spontaneous photocurrent with linear polarized light along to E1 and E2 direction. 0° and 180° correspond to E1 and E2 electrodes, respectively.
Figure 2c shows the I–V characteristics with various laser intensities from 2 to 360 μW measured between E1 and E2 electrodes. The spontaneous photocurrent at zero-bias voltage increases with increasing the laser intensities. The laser power dependence of spontaneous photocurrent is plotted in Fig. 2d. The spontaneous photocurrent linearly increases as a function of laser power in the weak power conditions below 5 μW, while the spontaneous photocurrent gradually saturates in the high power conditions. The behavior of nonlinear power dependence of spontaneous photocurrent is much different from the linear power dependence from photovoltaic responses of p–n junction and Schottky barrier45,46,47. The possible mechanism for the nonlinear spontaneous photocurrent is one of the second-order nonlinear optical responses, the shift current, which is caused in the system with broken P-symmetry arising from the shift of center of gravity electron position in real space before and after photoexcitation14. The nonlinear shift current Jshift as a function of excitation power P is described as follows:
where S0, S1, and S2 are coefficients, which contribute to the shift current4,48. When P is enough small, S2 becomes dominant compare with S1, and Jshift shows linear dependence as a function of P, as shown in the green dotted line in Fig. 2d. Moreover, S1 becomes dominant with increasing P and shows P1/2 power dependence, as shown in the red dotted line in Fig. 2d. The experimental result of spontaneous photocurrent as a function of excitation power is well reproduced by the calculated result using Eq. (1). This nonlinear photocurrent is much contradict to the linear photocurrent arising from Schottky barrier49, which implies that the experimentally observed spontaneous photocurrent comes from the shift current.
Figure 2e shows the spontaneous photocurrent mapping in MoS2/CrPS4 vdW heterostructure between E1 and E2 under laser light illumination of 532 nm and an excitation power of 600 μW. The positive and negative photocurrent signals around each electrode due to Schottky barrier internal voltage between heterostructure and metal electrodes are clearly observed in the photocurrent mapping. More importantly, the large spontaneous photocurrent is observed in the center of heterostructure region far from electrodes (see Fig. S4), and the spontaneous photocurrent in the center strongly depends on the measurement direction (see Fig. S5). These results strongly imply that the experimentally observed spontaneous photocurrent in the heterostructure region comes from intrinsic photovoltaic properties in the monolayer semiconductor/CrPS4 heterointerface.
Figure 2f shows the laser polarization angle dependence of spontaneous photocurrent in MoS2/CrPS4 vdW heterostructure (also see in Fig. S6), in which the linearly polarization angle of incident laser light is defined as relative angle from the mirror-plane (x-axis) of heterointerface. The polar plot of spontaneous photocurrent as a function of polarization angle shows weakly anisotropic response with two-fold symmetry, along with symmetric axis of parallel to mirror-plane in MoS2/CrPS4 vdW heterointerface. According to the theoretical calculation, the polar plot of the spontaneous bulk photovoltaic effect with only monolayer MoS2 with C3 symmetry is expected to show threefold symmetry and both positive and negative signals33,50; however, the polar plot of the spontaneous photocurrent of the MoS2/CrPS4 vdW heterostructure shows twofold symmetry along the spontaneous polarization direction and consistently positive signals, as shown in Fig. 2f. Thus, the experimentally observed spontaneous photocurrent is caused by the shift current induced by the broken P-symmetry at the MoS2/CrPS4 vdW heterointerface. However, these results are characteristic of bulk photovoltaics, which may not occur due to the shift current alone. In addition to the shift current, the ballistic current might also be considered a bulk photovoltaic effect that occurs under linearly polarized light excitation51,52. However, the major difference between the shift current and ballistic current is the response to circularly polarized light53,54. As shown in Fig. S7, the spontaneous photocurrent in the MoS2/CrPS4 heterostructure device disappears under circularly polarized light (CPL), suggesting that the effect of the ballistic current is negligible. The measured spontaneous current under CPL in Fig. S7 comes from a nonmagnetic injection current, for example, from a ballistic current induced by CPL. The experimentally observed injection current is a novel result that has not been reported for artificial vdW heterointerfaces, which provides new insights into the bulk photovoltaic effect at artificial vdW heterointerfaces.
The nonlinear spontaneous photocurrent induced by the breaking of T-symmetry in addition to P-symmetry is investigated in the MoS2/CrPS4 vdW heterostructure, because the vdW heterointerface is formed between the monolayer semiconductor and magnetic material of CrPS4. Figure 3a shows the temperature dependence of I–V curves in the MoS2/CrPS4 vdW heterostructure under the illumination of laser with a wavelength of 532 nm and power of 600 μW. With decreasing temperature from 300 to 40 K, the gradient of I–V curve decreases and open-circuit voltage increases. The fill factor is ~0.25 independent of temperature, as shown in Fig. S8, due to the linear I‒V characteristics of the bulk photovoltaic effect. The effective series resistances in the vdW heterostructure are evaluated from the gradient of the linear I‒V curves. The lower panel of Fig. 3b shows the effective series resistance (blue dot and line) and open-circuit voltage (green dot and line) of MoS2/CrPS4 vdW heterostructure as a function of temperature. The effective series resistance increases with decreasing temperature until 40 K, which corresponds to the temperature dependence of resistivity in monolayer MoS255,56. Moreover, the open-circuit voltage also increases with decreasing temperature above 40 K.
a Temperature dependence of I–V characteristics of MoS2/CrPS4 vdW heterostructure under the light illumination from 10 to 200 K. b Spontaneous photocurrent at zero-bias voltage as a function of temperature in the upper panel. The inset shows the temperature dependence of spontaneous photocurrent, and optical image in another MoS2/CrPS4 vdW heterostructure device. The open-circuit voltage, as indicated by green dots and lines in the lower panel and effective series resistance calculated by the gradient of I–V curve, as indicated by the blue dots and line in lower panel. The black dotted line at 40 K indicates Neel temperature of CrPS4.
Figure 3a shows the drastically change of I–V curve with decreasing temperature below 40 K. The spontaneous photocurrent shows almost constant values above 40 K as shown in Fig. 3a, while the most significant change in the temperature dependence of I–V curve is drastically decrease of spontaneous photocurrent below ∼40 K. Figure 3b shows the plot of spontaneous photocurrent as a function of temperature. The critical decrease of spontaneous photocurrent is celery observed below 40 K. Moreover, the trend of open-circuit voltage also changes below the critical temperature of 40 K, as shown in the lower panel of Fig. 3b.
The critical temperature of 40 K well corresponds to the magnetic transition temperature from paramagnetic to anti-ferromagnetic (AFM) phase of CrPS4 as Neel temperature (TN = 38 K)57,58,59,60. It is expected that the shift current as physical origin of spontaneous photocurrent shows temperature independent behavior, because it comes from the center of gravity position shift of excited electrons in the photoexcitation process, which is not to be affected by the defect and atomic registry61,62. However, the spontaneous photocurrent significantly decreases below Neel temperature of 40 K in CrPS4, which strongly implies the physical mechanism of nonlinear spontaneous photocurrent in addition to the shift current in the system with broken T-symmetry and P-symmetry of MoS2/CrPS4 heterointerface at low temperature.
We will discuss the anomalous and critical change of spontaneous photocurrent below 40 K. The shift current is described as the product of terms of optical transition probability and shift vector14. Noted that the optical transition probability measured by the differential reflectance spectra in the vdW heterostructure does not change below 40 K of Neel temperature in the multi-layers CrPS4 (see in Fig. S9), which suggests that the factor of optical transition probability is not the main physical reason of the critical change of spontaneous photocurrent. The magnetic phase change of CrPS4 at the heterointerface would affect the shift vector, however, it has revealed that the shift vector itself does not depend on the T-symmetry63. The magnetic lattice distortion accompanied by magnetic phase transition would also cause the possibility of change of shift-vector64, however, we could not observe any clear changes of Raman spectrum below 40 K as shown in Fig. S10. Moreover, the temperature dependence of lattice constant in bulk CrPS4, especially, x-axis along to expected polarization direction shows continuously change from 300 to 10 K straddling 40 K according to the previous result39 (see Fig. S11). Noted that the change of lattice constant is small value of only about 0.03% between 40 and 10 K. These are much contradict to the experimental results of constant values of spontaneous photocurrent from 300 to 40 K and critical change below 40 K, as shown Fig. 3a. Moreover, the spontaneous photocurrent also shows different behavior of clear enhancement below Neel temperature in another device of MoS2/CrPS4 vdW heterostructure, as shown in in the inset of Figs. 3b and S12. These experimental results strongly suggest that the change of optical transition probability and shift vector induced by magnetic lattice distortion cannot explain the reversible change of shift current depending on the device. Thus, the experimentally observed significant and critical change of spontaneous photocurrent below 40 K does not come from the change of shift current.
As described above, the shift current does not be affected by T-symmetry of the system, although, the experimental results of spontaneous photocurrent in MoS2/CrPS4 vdW heterostructure strongly depend on the magnetic state of CrPS4 layer, which implies additional nonlinear photocurrent mechanism in the system with broken P– and T-symmetry. The recent theoretical studies of nonlinear photocurrent predict the generation of magnetic injection current due to imbalance photoexcitation of electrons in momentum space in layered magnetic materials such as CrPS4 with the system with broken P– and T-symmetry19,22,23. The spontaneous photocurrent in AFM CrPS4 below Neel temperature (TN ∼ 40 K) might be affected by the generation of magnetic injection current. As shown in Fig. S13, bulk CrPS4 does not have a spontaneous photocurrent even below the Neel temperature, which suggests that the magnetic injection current is induced by a system with broken P-symmetry, such as the heterointerface of MoS2 and CrPS4. The experimental result of the critical decrease in the spontaneous photocurrent shown in Fig. 3a (also shown in Fig. S12) comes from the generation of a magnetic injection current with a negative sign superimposed on the temperature-independent shift current, which will be discussed later. The generation of a magnetic injection current and shift current due to a decrease in temperature and a change in the magnetic order state are shown in Table S1.
In order to experimentally investigate the relationship between spontaneous photocurrent and magnetic states of CrPS4, we measured external magnetic field dependence of photocurrent in the vdW heterointerface below 40 K. Figure 4a, and b show the I–V curves in MoS2/CrPS4 vdW heterostructure with applying out of plane magnetic fields at 10 and 35 K below Neel temperature. The relationship between the magnetic state of CrPS4 at each temperature and the out-of-plane magnetic field is shown in Fig. S14. The I–V curve changes and the spontaneous photocurrent increases with the sweep of out of plane magnetic field from 0 to 3 T (from 0 to −3 T) at 10 K, as shown in Fig. 4a. Figure 4c shows the spontaneous photocurrent as a function of out of plane magnetic field at 10 K. Figure 4c and d show the results under the sweeping of magnetic field from 0 T. The effect of hysteresis on the spontaneous photocurrent is shown in Fig. S15. The spontaneous photocurrent quickly increases at the boundaries of ±2 T, which is caused by the magnetic field induced phase transition from A-type AFM with out-of-plane ferromagnetic ordered spins to canted-antiferromagnetic state with ordered canted spins within a layer (A-AFM) and canted anti-ferromagnetic ordered spins (CAFM) of CrPS460. The experimental result of increase of spontaneous photocurrent in Fig. 4c comes from decrease of negative sign magnetic injection current depending on the magnetic phase of CrPS4 superimposed to shift current triggered by phase transition from A-AFM to CAFM of CrPS4 by external out of plane magnetic field in the vdW heterostructure, because the value of magnetic injection current in A-AFM state is larger than that in CAFM state. As shown in Fig. S16, electrical resistance R is constant with respect to the external magnetic field; thus, the change in spontaneous photocurrent clearly does not result from the change in carrier mobility.
a and b I–V characteristics of MoS2/CrPS4 vdW heterostructure with external out of plane magnetic field from −7 to 7 T at 10 K (a) and 35 K (b). c and d External magnetic field dependence of spontaneous photocurrent is represented by red dots at 10 K (c) and 35 K (d). Each colored region shows the magnetic state of CrPS4, ferromagnetic (FM, blue), canted anti-ferromagnetic (CAFM, green) and A-type anti-ferromagnetic (A-AFM, red), respectively60. The black dotted line in d shows the value of shift current above 40 K. The schematic of crystal and spin structures of 1L-MoS2/CrPS4 vdW heterostructure are shown in the figures.
The I–V curve changes and the spontaneous photocurrent increases with the sweep of out of plane magnetic field from 0 to 7 T (from 0 to −7 T) at 35 K, as shown in Fig. 4b. Figure 4d shows the magnetic field dependence of spontaneous photocurrent at 35 K near Neel temperature. The spontaneous photocurrent increases with the sweep of out of plane magnetic field from 3 to 7 T (from −3 to −7 T) at 35 K. The spontaneous photocurrent also quickly increases at the boundaries of ±4 T, which is caused by the magnetic field induced phase transition from CAFM to ferromagnetic (FM) ordered state of CrPS4. Above external magnetic field of ±4 T, the values of spontaneous photocurrent reach to almost same value without magnetic field above Neel temperature of 40 K, which is indicated by the dotted line in Fig. 4d. The stepwise increase of spontaneous photocurrent in Fig. 4d comes from the disappearance of magnetic injection current and residual shift current in the spontaneous photocurrent by magnetic phase transition from CAFM to FM of CrPS4 by external magnetic field.
The sign of magnetic injection current is determined by the up- and down-spin of top layer in the AFM state, and reversed AFM19,22,23. The two-types of heterointerface of MoS2/CrPS4 vdW heterointerface are possible in AFM, and reversed-AFM of CrPS4 below Neel temperature (TN). The experimental results of critical increase, and decrease of spontaneous photocurrent induced by A-AFM transition, as shown in Figs. 3a, and S12 are well consistent with the cases of vdW heterointerface with AFM, and reversed-AFM of CrPS4, respectively. The magnetic state switchable spontaneous photocurrent phenomena described above are understood by the change of magnetic injection current superimposed to shift current in vdW heterointerface. These results strongly imply the experimental observation of characteristic phenomena of nonlinear spontaneous photocurrent in vdW heterostructure with the system with broken P– and T– symmetry.
We studied nonlinear photocurrent responses of MoS2/CrPS4 vdW heterostructure with the system with broken P– and T-symmetry. The finite spontaneous photocurrent arising from shift current along the parallel axis to mirror plane at the interface of MoS2/CrPS4 has been observed. Moreover, we demonstrated that the spontaneous photocurrent drastically changes below Neel temperature of A-type AFM CrPS4 in MoS2/CrPS4 heterostructure. The spontaneous photocurrent also changes depending on external magnetic field below the Neel temperature, accompanied by field induced magnetic phase transition. The critical suppression (enhancement) of spontaneous photocurrent below Neel temperature is caused by competition of the shift current and sign of magnetic injection current in MoS2/CrPS4 vdW heterointerface. Our results of magnetic switchable photovoltaic responses demonstrated here provide the new aspects on the nonlinear photovoltaic effects in P– and T-symmetry breaking vdW heterointerface, and new strategy for next-generation solar cells.
Monolayer (1L) MoS2 and thick multi-layers CrPS4 were prepared on 270-nm-thick SiO2 on Si substrates by mechanical exfoliation from their respective bulk single crystals. The thickness of MoS2 was determined from the optical contrast and photoluminescence (PL) spectra. The MoS2/CrPS4 heterostructure was fabricated by a polydimethylsiloxane (PDMS)-based viscoelastic transfer technique using poly-methyl methacrylate (PMMA) stamp. The PMMA layer was washed away by immersing the sample in an acetone solution. The microelectrode pattern was fabricated by photolithography method, and Bi/Au electrodes were thereafter fabricated by thermal evaporation method. The stacking angle (theta) defined by the relative angle between zigzag direction of 1L-MoSe2 and a-axis of CrPS4 in the heterostructure was evaluated to be 0(,pm ,1^{circ}) by the edge angle in optical image38,39,65. The correspondence between the characteristic edge angles and the crystal structure was confirmed by polarized Raman scattering and SHG measurements (Figs. S17 and S1)8,66,67.
A linearly polarized green laser (532 nm) was used as an excitation light source for the photocurrent measurements. The I–V characteristics of the device was measured in the shield box (Keithley, 8101-PIV) at room temperature and in the cryostat (Janis Research, ST-500-UC) for the temperature variable measurements, respectively. The micro-Raman setup (Nanophoton, Ramantouch) was used for the measurement of PL, Raman scattering, and differential reflectance spectra. The source-meter (Keithley, 2636B) was used for applying the bias voltage and measure of current.
A linearly polarized green laser (520 nm) was used as an excitation light source for I–V characteristics measurement under out of plane magnetic field. The device was cooled by the He-flow cryostat (Janis Research, ST-500), and the magnetic field was generated by the superconductive magnet (Cryogenic, mCFM). The sourcemeter (Keithley, 2614B) was used for applying the bias voltage and measuring the current under magnetic fields.
Data presented in this paper and the supplementary materials are available from the corresponding author upon request.
Nakamura, M. et al. Shift current photovoltaic effect in a ferroelectric charge-transfer complex. Nat. Commun. 8, 281 (2017).
Article ADS PubMed PubMed Central CAS Google Scholar
Ma, J. et al. Nonlinear photoresponse of type-II Weyl semimetals. Nat. Mater. 18, 476–481 (2019).
Article ADS PubMed CAS Google Scholar
Cook, A. M., M Fregoso, B., de Juan, F., Coh, S. & Moore, J. E. Design principles for shift current photovoltaics. Nat. Commun. 8, 14176 (2017).
Article ADS PubMed PubMed Central CAS Google Scholar
Zhang, Y. et al. Switchable out-of-plane shift current in ferroelectric two-dimensional material CuInP2S6. Appl. Phys. Lett. 120, 013103 (2022).
Article ADS CAS Google Scholar
Huang, Y.-S., Chan, Y.-H. & Guo, G.-Y. Large shift currents via in-gap and charge-neutral excitons in a monolayer and nanotubes of BN. Phys. Rev. B 108, 75413 (2023).
Article ADS CAS Google Scholar
Ebrahimian, A., Dadsetani, M. & Asgari, R. Shift current in molecular crystals possessing charge-transfer characteristics. Phys. Rev. Appl. 19, 44006 (2023).
Article ADS CAS Google Scholar
Dong, Y. et al. Giant bulk piezophotovoltaic effect in 3R-MoS2. Nat. Nanotechnol. 18, 36–41 (2023).
Article ADS PubMed CAS Google Scholar
Li, Z. et al. An anisotropic van der Waals dielectric for symmetry engineering in functionalized heterointerfaces. Nat. Commun. 14, 5568 (2023).
Article ADS PubMed PubMed Central CAS Google Scholar
Yang, S. Y. et al. Above-bandgap voltages from ferroelectric photovoltaic devices. Nat. Nanotechnol. 5, 143–147 (2010).
Article ADS PubMed CAS Google Scholar
Glass, A. M., Linde, D. & Negran, T. J. High-voltage bulk photovoltaic effect and the photorefractive process in LiNbO3. Appl. Phys. Lett. 25, 233–235 (1974).
Article ADS CAS Google Scholar
Koch, W. T. H., Munser, R., Ruppel, W. & Würfel, P. Anomalous photovoltage in BaTiO3. Ferroelectrics 13, 305–307 (1976).
Article ADS CAS Google Scholar
Belinicher, V. I. & Sturman, B. I. The photogalvanic effect in media lacking a center of symmetry. Sov. Phys. Uspekhi 23, 199 (1980).
Article ADS Google Scholar
Sipe, J. E. & Shkrebtii, A. I. Second-order optical response in semiconductors. Phys. Rev. B 61, 5337–5352 (2000).
Article ADS CAS Google Scholar
Young, S. M., Zheng, F. & Rappe, A. M. First-principles calculation of the bulk photovoltaic effect in bismuth ferrite. Phys. Rev. Lett. 109, 236601 (2012).
Article ADS PubMed Google Scholar
Morimoto, T. & Nagaosa, N. Topological nature of nonlinear optical effects in solids. Sci. Adv. 2, e1501524 (2016).
Article ADS PubMed PubMed Central Google Scholar
Sun, X. et al. Topological insulator metamaterial with giant circular photogalvanic effect. Sci. Adv. 7, eabe5748 (2023).
Article ADS Google Scholar
Zhang, Y. et al. Photogalvanic effect in Weyl semimetals from first principles. Phys. Rev. B 97, 241118 (2018).
Article ADS CAS Google Scholar
Gao, Y., Zhang, Y. & Xiao, D. Tunable layer circular photogalvanic effect in twisted bilayers. Phys. Rev. Lett. 124, 77401 (2020).
Article ADS CAS Google Scholar
Zhang, Y. et al. Switchable magnetic bulk photovoltaic effect in the two-dimensional magnet CrI3. Nat. Commun. 10, 3783 (2019).
Article ADS PubMed PubMed Central Google Scholar
Fei, R., Song, W. & Yang, L. Giant photogalvanic effect and second-harmonic generation in magnetic axion insulators. Phys. Rev. B 102, 35440 (2020).
Article ADS CAS Google Scholar
Watanabe, H. & Yanase, Y. Chiral photocurrent in parity-violating magnet and enhanced response in topological antiferromagnet. Phys. Rev. X 11, 11001 (2021).
CAS Google Scholar
Mu, X., Xue, Q., Sun, Y. & Zhou, J. Magnetic proximity enabled bulk photovoltaic effects in van der Waals heterostructures. Phys. Rev. Res. 5, 1 (2023).
Article ADS Google Scholar
Wang, H. & Qian, X. Electrically and magnetically switchable nonlinear photocurrent in РТ-symmetric magnetic topological quantum materials. NPJ Comput. Mater. 6, 199 (2020).
Kim, J. S. et al. Electrical transport properties of polymorphic MoS2. ACS Nano 10, 7500–7506 (2016).
Article PubMed CAS Google Scholar
Xie, D. et al. Coplanar multigate MoS2 electric-double-layer transistors for neuromorphic visual recognition. ACS Appl. Mater. Interfaces 10, 25943–25948 (2018).
Article PubMed CAS Google Scholar
Meng, Y. et al. Electrical switching between exciton dissociation to exciton funneling in MoSe2/WS2 heterostructure. Nat. Commun. 11, 2640 (2020).
Article ADS PubMed PubMed Central CAS Google Scholar
Kang, J., Li, J., Li, S.-S., Xia, J.-B. & Wang, L.-W. Electronic structural Moiré pattern effects on MoS2/MoSe2 2D heterostructures. Nano Lett. 13, 5485–5490 (2013).
Article ADS PubMed CAS Google Scholar
Zhang, N. et al. Moiré intralayer excitons in a MoSe2/MoS2 heterostructure. Nano Lett. 18, 7651–7657 (2018).
Article ADS PubMed CAS Google Scholar
Zhang, C. et al. Interlayer couplings, Moiré patterns, and 2D electronic superlattices in MoS2/WSe2 hetero-bilayers. Sci. Adv. 3, e1601459 (2023).
Article ADS Google Scholar
Lin, M.-L. et al. Moiré phonons in twisted bilayer MoS2. ACS Nano 12, 8770–8780 (2018).
Article PubMed CAS Google Scholar
Shinokita, K., Watanabe, K., Taniguchi, T. & Matsuda, K. Valley relaxation of the moiré excitons in a WSe2/MoSe2 heterobilayer. ACS Nano 16, 16862–16868 (2022).
Article PubMed CAS Google Scholar
Kim, H. et al. Dynamics of Moiré trion and its valley polarization in a microfabricated WSe2/MoSe2 heterobilayer. ACS Nano 17, 13715–13723 (2023).
Article PubMed CAS Google Scholar
Akamatsu, T. et al. A van der Waals interface that creates in-plane polarization and a spontaneous photovoltaic effect. Science 372, 68–72 (2021).
Article ADS PubMed CAS Google Scholar
Zhang, S. et al. Observation of the photovoltaic effect in a van der Waals heterostructure. Nanoscale 15, 5948–5953 (2023).
Article PubMed CAS Google Scholar
Hu, C., Naik, M. H., Chan, Y.-H., Ruan, J. & Louie, S. G. Light-induced shift current vortex crystals in moiré heterobilayers. Proc. Natl Acad. Sci. USA 120, e2314775120 (2023).
Article PubMed PubMed Central CAS Google Scholar
Strasser, A., Wang, H. & Qian, X. Nonlinear optical and photocurrent responses in Janus MoSSe monolayer and MoS2–MoSSe van der Waals heterostructure. Nano Lett. 22, 4145–4152 (2022).
Article ADS PubMed CAS Google Scholar
Sauer, M. O. et al. Shift current photovoltaic efficiency of 2D materials. NPJ Comput. Mater. 9, 35 (2023).
Article ADS CAS Google Scholar
Diehl, R. & Carpentier, C.-D. The crystal structure of chromium thiophosphate, CrPS4. Acta Crystallogr. 33, 1399–1404 (1977).
Article Google Scholar
Lee, J. et al. Structural and optical properties of single- and few-layer magnetic semiconductor CrPS4. ACS Nano 11, 10935–10944 (2017).
Article PubMed CAS Google Scholar
Zhao, W. et al. Metastable MoS2: crystal structure, electronic band structure, synthetic approach and intriguing physical properties. Chem. Eur. J. 24, 15942–15954 (2018).
Article PubMed CAS Google Scholar
Kim, S., Lee, J., Lee, C. & Ryu, S. Polarized Raman spectra and complex raman tensors of antiferromagnetic semiconductor CrPS4. J. Phys. Chem. C 125, 2691–2698 (2021).
Article CAS Google Scholar
Houmes, M. J. A. et al. Highly anisotropic mechanical response of the Van der Waals magnet CrPS4. Adv. Funct. Mater. 34, 2310206 (2023).
Yang, J. et al. Edge orientations of mechanically exfoliated anisotropic two-dimensional materials. J. Mech. Phys. Solids 112, 157–168 (2018).
Article ADS MathSciNet CAS Google Scholar
Tiwari, R. P., Birajdar, B. & Ghosh, R. K. First-principles calculation of shift current bulk photovoltaic effect in two-dimensional α-In2Se3. Phys. Rev. B 101, 235448 (2020).
Article ADS CAS Google Scholar
Dharmadhikari, V. S. & Grannemann, W. W. Photovoltaic properties of ferroelectric BaTiO3 thin films rf sputter deposited on silicon. J. Appl. Phys. 53, 8988–8992 (1982).
Article ADS CAS Google Scholar
Kaner, N. T. et al. Enhanced shift currents in monolayer 2D GeS and SnS by strain-induced band gap engineering. ACS Omega 5, 17207–17214 (2020).
Article PubMed PubMed Central CAS Google Scholar
Pal, S. et al. Bulk photovoltaic effect in BaTiO3-based ferroelectric oxides: an experimental and theoretical study. J. Appl. Phys. 129, 084106 (2021).
Article ADS CAS Google Scholar
Chang, Y. R. et al. Shift-current photovoltaics based on a non-centrosymmetric phase in in-plane ferroelectric SnS. Adv. Mater. 35, 2301172 (2023).
Article CAS Google Scholar
Liu, W. et al. Graphene charge-injection photodetectors. Nat. Electron. 5, 281–288 (2022).
Article CAS Google Scholar
Sturman, B. I. & Fridkin, V. M. in The Photovoltaic and Photorefractive Effects in Non-Centrosymmetric Materials (Ferroelectricity and Related Phenomena), Vol. 8 (ed Taylor, G. W.) (Gordon and Breach Science, London, 1992).
Dai, Z. & Rappe, A. M. First-principles calculation of ballistic current from electron-hole interaction. Phys. Rev. B 104, 235203 (2021).
Article ADS CAS Google Scholar
Sturman, B. I. Ballistic and shift currents in the bulk photovoltaic effect theory. Phys.-Uspekhi 63, 407 (2020).
Article ADS Google Scholar
Belinicher, V. I., Ivchenko, E. L. & Sturman, B. I. Kinetic theory of the displacement photovoltaic effect in piezoelectrics. Sov. Phys. JETP 56, 2 (1982).
Google Scholar
Burger, A. M. et al. Direct observation of shift and ballistic photovoltaic currents. Sci. Adv. 5, eaau5588 (2024).
Article ADS Google Scholar
Cui, X. et al. Multi-terminal transport measurements of MoS2 using a van der Waals heterostructure device platform. Nat. Nanotechnol. 10, 534–540 (2015).
Article ADS PubMed CAS Google Scholar
Pei, Q. L. et al. Spin dynamics, electronic and thermal transport properties of two-dimensional CrPS4 single crystal. J. Appl Phys. 119, 4 (2016).
Article Google Scholar
Chen, Q., Ding, Q., Wang, Y., Xu, Y. & Wang, J. Electronic and magnetic properties of a two-dimensional transition metal phosphorous chalcogenide TMPS4. J. Phys. Chem. C 124, 12075–12080 (2020).
Article CAS Google Scholar
Peng, Y. et al. Controlling spin orientation and metamagnetic transitions in anisotropic van der Waals antiferromagnet CrPS4 by hydrostatic pressure. Adv. Funct. Mater. 32, 2106592 (2022).
Article CAS Google Scholar
Son, J. et al. Air-stable and layer-dependent ferromagnetism in atomically thin van der Waals CrPS4. ACS Nano 15, 16904–16912 (2021).
Article PubMed CAS Google Scholar
Peng, Y. et al. Magnetic structure and metamagnetic transitions in the van der Waals antiferromagnet CrPS4. Adv. Mater. 32, 2001200 (2020).
Article CAS Google Scholar
Nakamura, M. et al. Impact of electrodes on the extraction of shift current from a ferroelectric semiconductor SbSI. Appl. Phys. Lett. 113, 232901 (2018).
Article ADS Google Scholar
Hatada, H. et al. Defect tolerant zero-bias topological photocurrent in a ferroelectric semiconductor. Proc. Natl. Acad. Sci. USA 117, 20411–20415 (2020).
Article ADS PubMed PubMed Central CAS Google Scholar
Qian, Z., Zhou, J., Wang, H. & Liu, S. Shift current response in elemental two-dimensional ferroelectrics. NPJ Comput. Mater. 9, 67 (2023).
Article ADS CAS Google Scholar
Schankler, A. M., Gao, L. & Rappe, A. M. Large bulk piezophotovoltaic effect of monolayer 2H-MoS2. J. Phys. Chem. Lett. 12, 1244–1249 (2021).
Article PubMed CAS Google Scholar
Tinoco, M., Maduro, L. & Conesa-Boj, S. Metallic edge states in zig-zag vertically-oriented MoS2 nanowalls. Sci. Rep. 9, 15602 (2019).
Article ADS PubMed PubMed Central Google Scholar
Mennel, L., Paur, M. & Mueller, T. Second harmonic generation in strained transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2, and WSe2. APL Photonics 4, 034404 (2018).
Article ADS Google Scholar
Hou, D. et al. Extraordinary magnetic second harmonic generation in monolayer CrPS4. Adv. Opt. Mater. 12, 2400943 (2024).
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This work was supported by JSPS KAKENHI (Grant Nos. JP16H00910, JP16H06331, JP17H06786, JP19K14633, JP19K22142, JP20H05664, JP21H05232, JP21H05235, JP21H01012, JP21H05233, JP22K18986 and JP23KJ1381), JST FOREST program (Grant No. JPMJFR213K), JST CREST program (Grant No. JPMJCR24A5), the Collaboration Program of the Laboratory for Complex Energy Processes, Institute of Advanced Energy, Kyoto University. Growth of h-BN was supported from Grant Nos. JPMXP0112101001, JSPS KAKENHI and JP20H00354.
Institute of Advanced Energy, Kyoto University, Uji, Kyoto, 611-0011, Japan
Shuichi Asada, Keisuke Shinokita & Kazunari Matsuda
Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
Kenji Watanabe
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
Takashi Taniguchi
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S.A. contributed to the fabrication of samples studied in this work. S.A., K.S., and K.M. designed the experiments, which were performed by S.A. K.W. and T.T. provided h-BN crystal which used in samples. Data analysis was performed by S.A. and K.M. The draft was written by S.A., K.S., and K.M., with all authors contributing to reviewing and editing. The project was supervised by K.M.
Correspondence to Kazunari Matsuda.
The authors declare no competing interests.
Nature Communications thanks the anonymous reviewer(s) for their contribution to the peer review of this work. A peer review file is available.
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Asada, S., Shinokita, K., Watanabe, K. et al. Nonlinear photovoltaic effects in monolayer semiconductor and layered magnetic material hetero-interface with P– and T-symmetry broken system. Nat Commun 16, 4827 (2025). https://doi.org/10.1038/s41467-025-58918-9
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