Bifacial all-perovskite tandem solar cells

The efficiency of all-perovskite tandem devices falls far below theoretical efficiency limits, mainly because a widening bandgap fails to increase open-circuit voltage. We report on a bifacial all-perovskite tandem structures with an equivalent efficiency of 29.3% under back-to-front irradiance ratio of 30. This increases energy yield and reduces the required bandgap of a wide-bandgap cell. Open-circuit voltage deficit is therefore minimized, although its performance under only front irradiance is not ideal. The bifacial device needs a sputtered rear transparent electrode, which could reduce photon path length and deteriorate stability of Pb-Sn perovskites. Embedding a light-scattering micrometer-sized particle layer into perovskite to trap light, effectively increases absorptance by 5 to 15% in the infrared region. Using a nonacidic hole transport layer markedly stabilizes the hole-extraction interface by avoiding proton-accelerated formation of iodine. These two strategies together increase efficiency of semitransparent Pb-Sn cells from 15.6 to 19.4%, enabling fabrication of efficient bifacial all-perovskite tandem devices.

University of North Carolina, Arizona State University (ASU)

Bo Chen and Zhenhua Yu and Arthur Onno and Zhengshan Yu and Shangshang Chen and Jiantao Wang and Zachary C. Holman and Jinsong Huang

Science advances

2022

11

10.1126/SCIADV.ADD0377/SUPPL_FILE/SCIADV.ADD0377_SM.PDF

23752548

47

eadd0377

36427306

NLM (Medline)

8