Strain Modulation for Light‐Stable n–i–p Perovskite/Silicon Tandem Solar Cells

• Published in: Advanced materials (Weinheim) 2022-07, Vol.34 (26), p.e2201315-n/a
• Main Authors: Wang, Lina, Song, Qizhen, Pei, Fengtao, Chen, Yihua, Dou, Jie, Wang, Hao, Shi, Congbo, Zhang, Xiao, Fan, Rundong, Zhou, Wentao, Qiu, Zhiwen, Kang, Jiaqian, Wang, Xueyun, Lambertz, Andreas, Sun, Mengru, Niu, Xiuxiu, Ma, Yue, Zhu, Cheng, Zhou, Huanping, Hong, Jiawang, Bai, Yang, Duan, Weiyuan, Ding, Kaining, Chen, Qi
• Format: Article
• Language: English
• Subjects: Absorbers; Adenosine triphosphate; Circuits; Compressive properties; Energy conversion efficiency; Energy gap; Ion migration; Materials science; Maximum power; Modulation; open‐circuit voltage; perovskite/silicon tandem solar cells; Perovskites; phase segregation; Photovoltaic cells; Silicon; Solar cells; strain modulation; Tensile strain
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202201315

Perovskite/silicon tandem solar cells are promising to penetrate photovoltaic market. However, the wide‐bandgap perovskite absorbers used in top‐cell often suffer severe phase segregation under illumination, which restricts the operation lifetime of tandem solar cells. Here, a strain modulation strategy to fabricate light‐stable perovskite/silicon tandem solar cells is reported. By employing adenosine triphosphate, the residual tensile strain in the wide‐bandgap perovskite absorber is successfully converted to compressive strain, which mitigates light‐induced ion migration and phase segregation. Based on the wide‐bandgap perovskite with compressive strain, single‐junction solar cells with the n–i–p layout yield a power conversion efficiency (PCE) of 20.53% with the smallest voltage deficits of 440 mV. These cells also maintain 83.60% of initial PCE after 2500 h operation at the maximum power point. Finally, these top cells are integrated with silicon bottom cells in a monolithic tandem device, which achieves a PCE of 26.95% and improved light stability at open‐circuit. A strain modulation strategy to constrain phase segregation in a wide‐bandgap perovskite absorber by reinforcing the energy barrier for ion migration is reported. With compressive strain, the single‐junction devices yield one of smallest voltage deficits of 440 mV. Moreover, the resulting perovskite/silicon tandem solar cells achieve a champion efficiency of 26.95% with improved light stability at open‐circuit.