Shanghai Jiao Tong University Journal Center
image:
(a) Schematic diagram illustrating the principle of the three-point bending test;
(b) experimental setup for the three-point bending test;
(c) load-displacement responses of silicon wafers with different thicknesses;
(d) SEM image of silicon surface with large-sized pyramids；
(e)SEM image of silicon surface with small-sized pyramids;
(f) load-displacement responses of silicon wafers with different pyramid sizes.
view more
(a) Schematic diagram illustrating the principle of the three-point bending test;
(b) experimental setup for the three-point bending test;
(c) load-displacement responses of silicon wafers with different thicknesses;
(d) SEM image of silicon surface with large-sized pyramids；
(e)SEM image of silicon surface with small-sized pyramids;
(f) load-displacement responses of silicon wafers with different pyramid sizes.
Credit: Qi Liu, Junjun Li, Fei Wang, Shuangbiao Xia, Yuhui Ji, Yutao Wang, Yunren Luo, Jian Yu, Fanying Meng, Liping Zhang, Zhengxin Liu & Wenzhu Liu.
Crystalline silicon solar cells currently dominate the global photovoltaic market, and combining them with wide-bandgap perovskite solar cells has successfully pushed power conversion efficiency limits even further. However, creating lightweight and flexible versions of these tandem cells has been severely hindered by mechanical interfacial stress between the silicon bottom cell and the perovskite top cell, which often leads to delamination and device degradation.
Now, a team of researchers from the Shanghai Institute of Microsystem and Information Technology (SIMIT) of the Chinese Academy of Sciences, alongside collaborators from the University of Chinese Academy of Sciences and Southwest Petroleum University, has developed an innovative solution to this structural challenge.
In a study published in ENGINEERING Energy, the researchers demonstrated that reducing both the thickness of the silicon wafer and the size of the surface texturing pyramids significantly improves the wafer's flexural strength. Standard V-shaped valleys between large silicon pyramids act as stress concentration points, making thin wafers prone to cracking under bending. By minimizing these pyramid structures, the stress concentration is alleviated, dramatically enhancing the material's mechanical flexibility.
To achieve this, the team employed a synergistic optimization strategy, using a precisely controlled wet-etching process to fabricate small-sized, high-density, and highly uniform submicron pyramids on ultrathin 55 µm silicon wafers. They identified that an optimal etching duration of 360 seconds produced a dense array of uniformly sized pyramids (ranging from 800 nm to 1.7 µm) that perfectly balanced optical light-trapping capabilities with mechanical stability.
This optimal submicron texture yielded a cascade of device improvements:
As a proof of concept, monolithic flexible perovskite/silicon tandem solar cells built upon these uniformly textured 55 µm wafers achieved a remarkable steady-state power conversion efficiency (PCE) of 30.04%. The optimized devices demonstrated stable power output and negligible hysteresis.
This breakthrough provides a highly effective surface engineering strategy to resolve the conflict between optical performance and mechanical stability in thin silicon wafers. The resulting highly efficient and mechanically robust devices hold immense potential for the future of low-cost, lightweight, and flexible photovoltaic applications, including aerospace technology, building-integrated photovoltaics, and wearable electronic devices.
Journal: ENGINEERING Energy
Read the full article for free: https://rdcu.be/flL64
Cite this article: Liu, Q., Li, J., Wang, F. et al. Enhanced performance and flexibility of perovskite/silicon tandem solar cells via uniform submicron pyramids. ENG. Energy 20, 10704 (2026). https://doi.org/10.1007/s11708-026-1070-4
ENGINEERING Energy
10.1007/s11708-026-1070-4
News article
Enhanced performance and flexibility of perovskite/silicon tandem solar cells via uniform submicron pyramids
20-May-2026
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.
Media Contact
Bowen Li
Shanghai Jiao Tong University Journal Center
qkzx@sjtu.edu.cn
Office: 021-62800059
Shanghai Jiao Tong University Journal Center
Copyright © 2026 by the American Association for the Advancement of Science (AAAS)
Copyright © 2026 by the American Association for the Advancement of Science (AAAS)
