Laboratory of Photonics and Interfaces, Department of Chemistry and Chemical Engineering, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany.
Science. 2017 Nov 10;358(6364):768-771. doi: 10.1126/science.aam5655. Epub 2017 Sep 28.
Perovskite solar cells (PSCs) with efficiencies greater than 20% have been realized only with expensive organic hole-transporting materials. We demonstrate PSCs that achieve stabilized efficiencies exceeding 20% with copper(I) thiocyanate (CuSCN) as the hole extraction layer. A fast solvent removal method enabled the creation of compact, highly conformal CuSCN layers that facilitate rapid carrier extraction and collection. The PSCs showed high thermal stability under long-term heating, although their operational stability was poor. This instability originated from potential-induced degradation of the CuSCN/Au contact. The addition of a conductive reduced graphene oxide spacer layer between CuSCN and gold allowed PSCs to retain >95% of their initial efficiency after aging at a maximum power point for 1000 hours under full solar intensity at 60°C. Under both continuous full-sun illumination and thermal stress, CuSCN-based devices surpassed the stability of spiro-OMeTAD-based PSCs.
钙钛矿太阳能电池（PSCs）的效率超过 20%，仅使用昂贵的有机空穴传输材料才能实现。我们展示了使用碘化铜（CuSCN）作为空穴提取层的 PSCs，其稳定效率超过 20%。快速的溶剂去除方法能够形成致密、高度共形的 CuSCN 层，从而促进快速载流子提取和收集。这些 PSCs 在长期加热下表现出很高的热稳定性，尽管它们的工作稳定性较差。这种不稳定性源于 CuSCN/Au 接触的电位诱导降解。在 CuSCN 和金之间添加导电还原氧化石墨烯间隔层，使得 PSCs 在 60°C 下，在全太阳光强度下以最大功率点老化 1000 小时后，仍能保持初始效率的>95%。在连续全日照和热应力下，基于 CuSCN 的器件超过了基于 spiro-OMeTAD 的 PSCs 的稳定性。
