Xu Zhenhua, Ng Chi Huey, Zhou Xinming, Li Xiaohui, Zhang Putao, Teo Siow Hwa
Key Laboratory of Photovoltaic Materials, Henan University, Kaifeng, Henan, 475004, China.
Institute of New Energy Technology, College of Information Science and Technology, Jinan University, Guangzhou, 510632, China.
Nanoscale. 2022 Aug 25;14(33):12090-12098. doi: 10.1039/d2nr03754h.
An effective electron transport layer (ETL) plays a pivotal role in suppressing nonradiative recombination at the interface as well as promoting perovskite crystallization to facilitate electron extraction in perovskite solar cells (PSCs). Herein, a functional polymer, poly(amidoamine) (PM) dendrimer, is introduced to rationalize the morphology and electrical performance of SnO nanocrystals to construct an SnO charge transfer layer. PM offers an even SnO colloidal dispersion with a particle-size distribution of ∼10 nm, which prevents the agglomeration of nanocrystals significantly. The polymer-complexed SnO provides a uniform and dense ETL film without island-like agglomeration, yielding a large conductive layer superior to that of the control. Equally important, the wettability-improved SnO ETL with PM modification produces a high-quality perovskite film with larger grain size, resulting in a power conversion efficiency (PCE) of the champion n-i-p PSC of up to 22.93% with negligible hysteresis. Noticeably, the device based on SnO-PM maintained 71% of its initial PCE (only 49% for the control device) after storing in the ambient environment for 45 days (relative humidity of 30%-80%) without packaging.
有效的电子传输层（ETL）在抑制界面处的非辐射复合以及促进钙钛矿结晶以利于钙钛矿太阳能电池（PSC）中的电子提取方面起着关键作用。在此，引入一种功能性聚合物聚（酰胺胺）（PM）树枝状大分子，以优化SnO纳米晶体的形态和电学性能，构建SnO电荷转移层。PM能使SnO胶体均匀分散，粒径分布约为10 nm，显著防止了纳米晶体的团聚。聚合物复合的SnO提供了均匀致密的ETL薄膜，没有岛状团聚，形成了比对照更好的大导电层。同样重要的是，经PM改性的润湿性改善的SnO ETL产生了具有更大晶粒尺寸的高质量钙钛矿薄膜，使得冠军n-i-p PSC的功率转换效率（PCE）高达22.93%，滞后可忽略不计。值得注意的是，基于SnO-PM的器件在未封装的情况下于环境环境（相对湿度30%-80%）中储存45天后，仍保持其初始PCE的71%（对照器件仅为49%）。
