Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 1A4, Canada.
KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
Science. 2020 Mar 6;367(6482):1135-1140. doi: 10.1126/science.aaz3691.
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.
通过将带隙逐渐减小的太阳能电池堆叠起来形成串联结构，有可能克服光伏中的单结肖克利-奎塞尔限制。溶液处理钙钛矿的快速发展已经实现了超过 20%的钙钛矿单结效率。然而，这一过程尚未实现与具有行业相关性的纹理化晶体硅太阳能电池的单片集成。我们报告了将溶液处理的微米厚钙钛矿顶电池与全纹理化硅异质结底电池相结合的串联结构。为了克服微米厚钙钛矿中电荷收集的挑战，我们将硅金字塔底部的耗尽宽度提高了三倍。此外，通过在钙钛矿表面锚定自限性钝化剂（1-丁硫醇），我们提高了扩散长度，并进一步抑制了相分离。这些综合增强使钙钛矿-硅串联太阳能电池的独立认证功率转换效率达到 25.7%。这些器件在 85°C 下经过 400 小时的热稳定性测试后，性能损失可忽略不计，在 40°C 下经过 400 小时的最大功率点跟踪后，性能损失也可忽略不计。
