Krishna Anurag, Zhang Hong, Zhou Zhiwen, Gallet Thibaut, Dankl Mathias, Ouellette Olivier, Eickemeyer Felix T, Fu Fan, Sanchez Sandy, Mensi Mounir, Zakeeruddin Shaik M, Rothlisberger Ursula, Manjunatha Reddy G N, Redinger Alex, Grätzel Michael, Hagfeldt Anders
Laboratory of Photomolecular Science, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne Lausanne 1015 Switzerland
Laboratory of Photonics and Interfaces, École Polytechnique Fédérale de Lausanne Lausanne 1015 Switzerland.
Energy Environ Sci. 2021 Sep 16;14(10):5552-5562. doi: 10.1039/d1ee02454j. eCollection 2021 Oct 13.
We present a facile molecular-level interface engineering strategy to augment the long-term operational and thermal stability of perovskite solar cells (PSCs) by tailoring the interface between the perovskite and hole transporting layer (HTL) with a multifunctional ligand 2,5-thiophenedicarboxylic acid. The solar cells exhibited high operational stability (maximum powering point tracking at one sun illumination) with a stabilized (the time over which the device efficiency reduces to 80% after initial burn-in) of ≈5950 h at 40 °C and a stabilized power conversion efficiency (PCE) over 23%. The origin of high device stability and performance is correlated to the nano/sub-nanoscale molecular level interactions between ligand and perovskite layer, which is further corroborated by comprehensive multiscale characterization. These results provide insights into the modulation of the grain boundaries, local density of states, surface bandgap, and interfacial recombination. Chemical analysis of aged devices showed that molecular passivation suppresses interfacial ion diffusion and inhibits the photoinduced I release that irreversibly degrades the perovskite. The interfacial engineering strategies enabled by multifunctional ligands can expedite the path towards stable PSCs.
我们提出了一种简便的分子级界面工程策略，通过使用多功能配体2,5-噻吩二甲酸来定制钙钛矿与空穴传输层（HTL）之间的界面，以增强钙钛矿太阳能电池（PSC）的长期运行稳定性和热稳定性。该太阳能电池表现出高运行稳定性（在一个太阳光照下进行最大功率点跟踪），在40°C时的稳定化时间（器件效率在初始老化后降至80% 所需的时间）约为5950小时，稳定功率转换效率（PCE）超过23%。器件高稳定性和高性能的起源与配体和钙钛矿层之间的纳米/亚纳米级分子水平相互作用相关，这通过全面的多尺度表征得到了进一步证实。这些结果为晶界、局部态密度、表面带隙和界面复合的调制提供了见解。对老化器件的化学分析表明，分子钝化抑制了界面离子扩散，并抑制了不可逆地降解钙钛矿的光致碘释放。多功能配体实现的界面工程策略可以加快通往稳定PSC的道路。
