SnO2/ZnO as double electron transport layer for halide perovskite solar cells

The energy loss in perovskite solar cells (PSCs) is a key factor that limits the potential scope of photovoltaic performance. Herein, we introduce a double electron transport layer (DETL) that consists of SnO2/ZnO and use it to prepare methylammonium lead triiodide (MAPbI3)-based planar heterojunction PSCs for mitigating the energy loss. We investigated the photovoltaic properties of DETL PSCs concerning the varying thickness of the ZnO layer. The thickness of DETL in each device was measured using an electron probe microanalyzer. UV–vis-NIR spectroscopic as well as different microscopic techniques including SEM and AFM were employed for an in-depth investigation of the prepared devices. The best PSC device in our study showed a comparatively improved energy conversion efficiency (ECE) of 15.22% with an optimized thickness of ZnO up to 210 nm.