School of Engineering, Brown University, Providence, Rhode Island, 02912, USA.
Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA.
Nat Commun. 2019 Jan 3;10(1):16. doi: 10.1038/s41467-018-07951-y.
There has been an urgent need to eliminate toxic lead from the prevailing halide perovskite solar cells (PSCs), but the current lead-free PSCs are still plagued with the critical issues of low efficiency and poor stability. This is primarily due to their inadequate photovoltaic properties and chemical stability. Herein we demonstrate the use of the lead-free, all-inorganic cesium tin-germanium triiodide (CsSnGeI) solid-solution perovskite as the light absorber in PSCs, delivering promising efficiency of up to 7.11%. More importantly, these PSCs show very high stability, with less than 10% decay in efficiency after 500 h of continuous operation in N atmosphere under one-sun illumination. The key to this striking performance of these PSCs is the formation of a full-coverage, stable native-oxide layer, which fully encapsulates and passivates the perovskite surfaces. The native-oxide passivation approach reported here represents an alternate avenue for boosting the efficiency and stability of lead-free PSCs.
迫切需要消除目前卤化物钙钛矿太阳能电池（PSC）中的有毒铅，但目前的无铅 PSC 仍然存在效率低和稳定性差的关键问题。这主要是由于它们的光伏性能和化学稳定性不足。在此，我们展示了使用无铅全无机铯锡锗三碘化（CsSnGeI）固溶钙钛矿作为 PSC 的光吸收剂，实现了高达 7.11%的有前途的效率。更重要的是，这些 PSC 表现出非常高的稳定性，在 N 气氛下，在一个太阳光照下连续运行 500 小时后，效率仅下降不到 10%。这些 PSC 引人注目的性能的关键是形成全覆盖、稳定的本征氧化物层，该层完全封装和钝化钙钛矿表面。这里报道的本征氧化物钝化方法为提高无铅 PSC 的效率和稳定性提供了另一种途径。
