A paper published today in Matter & Light describes a drone-mounted receiver that converts an incoming green laser into electricity at 38.49% efficiency — a figure that nearly doubles the roughly 20% achieved by DARPA’s current laser power-beaming receiver and beats the 34% benchmark the U.S. Department of Energy records for the best perovskite-silicon tandem solar cells. The device — a perovskite laser cell-thermoelectric (PLC-TE) tandem — is the first published design of this kind built explicitly for aircraft integration rather than laboratory conditions alone, and it solved a thermal challenge that previous attempts at laser-powered drone charging had not confronted directly.
The research comes from Jianhua Han at the Civil Aviation University of China and collaborators at Tsinghua University. Their goal was not simply to hit an efficiency number but to engineer a complete system: a receiver that could be mounted to a drone wing, illuminated by a high-power laser, cooled during flight, and kept stable enough to deliver useful power to the aircraft’s propellers.
The commercial drone market faces a persistent ceiling: no matter how sophisticated a UAV becomes, its battery runs out. For logistics operators, wildfire monitors, disaster-relief coordinators, and reconnaissance planners, the hard limit is not the aircraft’s software or its sensors — it is the energy it can carry into the air. The AeroVironment RQ-11 Raven, the most widely deployed small military UAV in the world, has a maximum flight time of 60 to 90 minutes before it must be recovered and recharged.
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Laser power beaming has been studied as a solution for decades: beam energy from the ground to a photovoltaic receiver on the drone, and the drone never needs to land to recharge. The engineering challenge is not the concept — it is the efficiency and thermal stability of the receiver. Any photovoltaic device converts some of the incoming light to electricity and wastes the rest as heat. Under low-intensity sunlight, this heat is manageable. Under the concentrated, high-intensity beam of a power-class laser, the same device can be driven to temperatures that degrade its performance and threaten its structural integrity.
The receiver developed by Han’s team stacks two functional layers in a single compact package. The first is a perovskite photovoltaic layer, which absorbs incoming photons from the green laser and converts them to electricity via the standard photoelectric process. Perovskite’s tunable bandgap — its crystal structure allows the material’s energy absorption properties to be precisely adjusted by changing its chemical composition — makes it possible to engineer a layer that absorbs nearly all photons at the specific wavelength of the illuminating laser, rather than losing them to reflection or pass-through. For a narrowband laser source, this gives perovskite a significant advantage over silicon, which is optimized for the full solar spectrum and therefore less efficient when illuminated by a single wavelength.
The second layer is thermoelectric. The Seebeck effect — the physical phenomenon by which a temperature gradient across certain materials generates a voltage — allows the thermoelectric layer to harvest the heat generated by the photovoltaic conversion process and turn it into additional electrical output. The greater the temperature difference between the hot face (the laser-illuminated perovskite side) and the cool face (the ambient-air side), the more power the thermoelectric layer produces.
This is where the design gets unconventional. In initial testing, thermal imaging revealed that the high-power laser was driving the device to 80 to 90 degrees Celsius (176 to 194 degrees Fahrenheit). That level of heat is damaging to the perovskite layer’s conversion efficiency and potentially to the device’s long-term integrity. The research team’s response was to introduce nanocrystals of antimony triselenide (Sb₂Se₃) — an earth-abundant, low-toxicity semiconductor — into the PLC-TE architecture. The nanocrystals act as a thermal management layer, controlling the rate at which heat moves through the device and keeping the perovskite layer within an acceptable operating range without suppressing the temperature gradient that the thermoelectric layer needs to function.
A second, more elegant contribution came from the drone’s own physics. The continuous airflow generated by the aircraft’s spinning propellers actively cools the thermoelectric layer’s cool side, maintaining the ΔT — the temperature difference — that drives thermoelectric output. The drone’s flight operation and the receiver’s thermal management are therefore coupled: the same propellers that consume the electricity being generated also help produce it.
In any power-beaming system, a ground-based transmitter converts electrical power into a directed, high-intensity laser beam and aims it at a receiver on the aircraft. The receiver’s photovoltaic cells convert the incoming light back into electricity. The concept is physically identical to a solar panel — but instead of diffuse, broad-spectrum sunlight, the source is a concentrated, single-wavelength beam that can be engineered to match the receiver’s peak absorption window exactly.
This narrowband match is what allows the PLC-TE to exceed the performance of conventional solar-optimized perovskite tandems. The DOE’s 34% benchmark for perovskite-silicon tandem cells reflects performance under the full solar spectrum. The PLC-TE is not competing with solar panels under sunlight — it is a purpose-built receiver for a specific laser wavelength, and the 38.49% figure reflects that deliberate optimization, as detailed in the peer-reviewed paper.
The U.S. Defense Advanced Research Projects Agency’s Persistent Optical Wireless Energy Relay (POWER) program — currently the most ambitious laser power-beaming effort in the world — recorded its benchmark efficiency of roughly 20% from laser output to electrical output at its receiver, using an array of commercial photovoltaic cells arranged behind a parabolic mirror. DARPA’s own team acknowledged that the receiver was built in roughly three months and prioritized speed of construction over efficiency optimization. The program’s long-term goal — beaming more than 5 kilowatts over approximately 120 miles (193 kilometers) using a network of airborne relay drones — will require improvements in receiver efficiency that the PRAD receiver was not designed to provide.
The gap between 20% and 38.49% is not just an academic data point. Receiver efficiency determines how much laser power must be transmitted to deliver a given amount of useful energy to the drone. A receiver that converts 38% of incoming light, rather than 20%, needs roughly half the laser intensity to achieve the same power output. That matters for two reasons. First, it means smaller, lighter, and less costly transmitters can accomplish the same charging task. Second, it directly affects safety: the higher the laser intensity required to compensate for low receiver efficiency, the larger the hazard zone around the beam for birds, wildlife, and any person who might cross the path.
This is the unstated implication that the published efficiency figure carries: higher receiver efficiency is one of the primary engineering levers for making outdoor laser drone charging compatible with civilian airspace. The FAA classifies high-power outdoor laser beams under strict safety regulations, requiring advance notification for any outdoor laser operation that could affect aircraft, and prohibiting beams that could damage the eyes of anyone in the beam path. A power-beaming system that achieves its drone-charging goal at lower laser intensity clears those safety hurdles more easily.
The current demonstration used a drone model in a controlled laboratory environment, not a free-flying aircraft in open air. The paper’s authors named two engineering problems that must be solved before the system can be used outside: real-time laser tracking and beam-path safety.
Tracking is the harder of the two. A laser strong enough to charge a drone is also precisely directional — it cannot spray energy over a wide area and hope some of it reaches the receiver. It must maintain a continuous, precise lock on a receiver that may be banking, climbing, or buffeted by wind. Sub-milliradian pointing accuracy, sustained while the drone maneuvers, requires a targeting system with capabilities that have not been demonstrated for open-air civilian drone charging at scale. Private-sector companies working on military systems have made progress: PowerLight Technologies demonstrated kilowatt-class laser charging of a drone at altitudes up to 5,000 feet (1,524 meters) in a 2026 flight test with the U.S. Department of Defense. The U.S. Naval Research Laboratory demonstrated a dual-use laser — capable of beaming power and intercepting incoming drones from the same platform — in a field test in near-whiteout snow conditions in June 2026. Neither system used a PLC-TE receiver; both used conventional photovoltaic arrays.
Beam-path safety is the regulatory gate. The FAA reported 12,840 laser strikes on aircraft in 2024, from consumer laser pointers aimed at cockpits — incidents with vastly lower intensity than any power-beaming system. The regulatory framework for outdoor laser operations was not designed with high-power charging beams in mind, and clearing the certification pathway for civilian airspace will require both engineering solutions (auto-shutoff systems that respond faster than any biological hazard can occur) and new regulatory guidance.
Han’s team identified real-time tracking as the next development priority. Their stated next step is to test the PLC-TE device on a real lightweight drone in outdoor conditions — a substantially different test environment that will expose the design to aerodynamic turbulence, variable ambient lighting, and the geometric complexity of a moving beam-to-receiver link.
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The full paper — “Sb₂Se₃ nanocrystals enable efficient perovskite-thermoelectric tandem devices for laser-powered unmanned aerial vehicles,” by Han and collaborators at the Civil Aviation University of China and Tsinghua University — was published July 29, 2026, in Matter & Light (DOI: 10.1016/j.matlit.2026.100066).
The significance is not that the study proves laser drone charging will reach commercial deployment on a near-term timeline. It does not. What it demonstrates is that the materials and engineering approach for a laser-optimized photovoltaic-thermoelectric tandem receiver can achieve efficiency levels well above current military benchmarks — and that at least one of the core engineering problems blocking that path (thermal overload under high-power illumination) has a practical solution in nanocrystal thermal management and propeller-driven aerodynamic cooling.
As Han noted in a statement accompanying the publication: “Previous studies largely focused on the materials or the device itself. We wanted to think beyond the laboratory, to how the system could actually be integrated into an aircraft, cooled during operation, and made compatible with flight. It isn’t just a materials science problem; it’s an engineering one.”
That framing — moving from materials science to system engineering — is what separates this paper from prior laboratory demonstrations. Whether the PLC-TE design reaches free-flight outdoor testing, clears the FAA’s laser safety certification pathway, and eventually scales to practical deployment is still an open question. The efficiency number, and the thermal engineering behind it, establish that the materials side of the problem is further along than the military’s own receiver programs currently reflect.
In a laser-powered drone, a ground-based transmitter converts electricity into a directed, high-intensity laser beam and aims it at a receiver mounted on the aircraft. The receiver contains photovoltaic cells — similar in principle to a solar panel — that convert the incoming light back into electricity to power the drone’s motors and systems, or to charge onboard batteries. The new perovskite laser cell-thermoelectric (PLC-TE) receiver published today differs from previous designs in two ways: it stacks a photovoltaic perovskite layer with a thermoelectric layer to capture and reuse the heat generated during photovoltaic conversion (rather than wasting it), and it uses antimony triselenide nanocrystals to manage the extreme temperatures — up to 90 degrees Celsius (194 degrees Fahrenheit) — that a high-power laser produces in the receiver. Combined with aerodynamic cooling from the drone’s own propellers, the design achieved 38.49% conversion efficiency — compared to roughly 20% for the U.S. military’s current laser power-beaming receiver.
The higher a receiver converts incoming laser light into electricity, the less total laser power must be transmitted to deliver a given amount of useful energy to the drone. A receiver at 38% efficiency needs roughly half the laser intensity of one at 20% efficiency to achieve the same result. In practical terms, that means smaller and lower-power transmitters — which in turn means a smaller hazard zone around the beam for birds, people, and other aircraft that might cross the path. The FAA’s laser safety regulations require outdoor laser operations to stay below specific intensity thresholds to avoid eye damage and cockpit distraction hazards; a more efficient receiver makes it easier to operate within those limits while still delivering useful power. The efficiency gap between academic research and military programs is therefore not just a benchmark comparison — it directly affects the feasibility of civilian deployment.
Two engineering problems remain unsolved for open-air use. The first is real-time beam tracking: the laser transmitter must maintain a precise, continuous lock on the receiver as the drone moves, banks, and responds to wind — a sub-milliradian pointing challenge that requires autonomous targeting systems not yet demonstrated for civilian-scale open-air drone charging. The second is regulatory safety certification: the FAA’s framework for outdoor laser operations was developed for low-power lasers, and a power-class charging beam will require new certification procedures and engineering safeguards (such as instant auto-shutoff if anything interrupts the beam path) before it can operate in shared airspace. The research team’s stated next step is outdoor testing on a real lightweight drone, which will expose the PLC-TE design to conditions the laboratory cannot replicate.
The research team specifically identified reconnaissance (persistent aerial surveillance without landing cycles), logistics (last-mile delivery in remote areas where landing infrastructure is unavailable), and disaster relief (keeping UAVs airborne over wildfire zones, flood areas, or earthquake sites without returning for battery swaps) as the most viable early applications. These are all missions where a drone that can stay airborne continuously, rather than cycling between 60 and 90 minutes of flight and ground recharging, represents a qualitative operational advantage — not just a marginal battery improvement.
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