• DOI:10.1126/science.aaz3691
• Corpus ID: 212560453

Efficient tandem solar cells with solution-processed perovskite on textured crystalline silicon

@article{Hou2020EfficientTS,
  title={Efficient tandem solar cells with solution-processed perovskite on textured crystalline silicon},
  author={Yi Hou and Erkan Aydin and Michele De Bastiani and Chuanxiao Xiao and Furkan H. Isikgor and Ding‐Jiang Xue and Bin Chen and Hao Chen and Behzad Bahrami and Ashraful Haider Chowdhury and Andrew K. Johnston and Se-Woong Baek and Ziru Huang and Mingyang Wei and Yitong Dong and Joel Troughton and Rawan Jalmood and Alessandro J. Mirabelli and Thomas G. Allen and Emmanuel van Kerschaver and Makhsud I. Saidaminov and Derya Baran and Qiquan (Quinn) Qiao and Kai Zhu and Stefaan De Wolf and Edward. H. Sargent},
  journal={Science},
  year={2020},
  volume={367},
  pages={1135 - 1140}
}

• Yi Hou, Erkan Aydin, +23 authors E. Sargent
• Published 6 March 2020
• Materials Science
• Science

Growing perovskite on textured silicon Wide–band gap perovskites could boost the efficiency of silicon solar cells by forming tandem cells, but usually the perovskite must be grown on a smoothed side of the silicon cell because the material grown on the rough light-trapping side often does not fully coat the silicon surface and its rough texture is prone to phase separation. Hou et al. grew thick films of a perovskite with a band gap of ∼1.68 electron volts and used a passivant, 1-butanethiol, to limit its phase separation. The tandem cells had a certified power conversion efficiency of 25.7% and had negligible losses after 400 hours of operation. Science, this issue p. 1135 A passivant prevented phase separation of a thick, wide–band gap perovskite film grown on a pyramidal-textured silicon cell. Stacking solar cells with decreasing band gaps to form tandems presents the possibility of overcoming the single-junction Shockley-Queisser limit in photovoltaics. The rapid development of solution-processed perovskites has brought perovskite single-junction efficiencies >20%. However, this process has yet to enable monolithic integration with industry-relevant textured crystalline silicon solar cells. We report tandems that combine solution-processed micrometer-thick perovskite top cells with fully textured silicon heterojunction bottom cells. To overcome the charge-collection challenges in micrometer-thick perovskites, we enhanced threefold the depletion width at the bases of silicon pyramids. Moreover, by anchoring a self-limiting passivant (1-butanethiol) on the perovskite surfaces, we enhanced the diffusion length and further suppressed phase segregation. These combined enhancements enabled an independently certified power conversion efficiency of 25.7% for perovskite-silicon tandem solar cells. These devices exhibited negligible performance loss after a 400-hour thermal stability test at 85°C and also after 400 hours under maximum power point tracking at 40°C.