ZnO/SnO2 Double Electron Transport Layer Guides Improved Open Circuit Voltage for Highly Efficient CH3NH3PbI3‑Based Planar Perovskite Solar Cells
journal contributionposted on 2018-04-23, 00:00 authored by Duo Wang, Cuncun Wu, Wei Luo, Xuan Guo, Bo Qu, Lixin Xiao, Zhijian Chen
The electron transport layer (ETL), as an important component of planar perovskite solar cells (P-PSCs), can effectively extract photon-generated electrons from perovskites and convey them to the cathode; by this token, its properties directly determine the photovoltaic performances of P-PSCs. Herein, we introduce a ZnO/SnO2 double electron transport layer for CH3NH3PbI3-based P-PSCs, achieving a high open circuit voltage (VOC) of 1.15 V with the power conversion efficiency (PCE) of 19.1% when the SnO2-based devices have a VOC of 1.07 V and a PCE of 18.0%; to the best of our knowledge, this is the highest VOC obtained by using an inorganic electron transport layer for pure CH3NH3PbI3-based P-PSCs so far. This result demonstrates that a higher Fermi energy (EF) and conduction band minimum (ECBM) of ETL could drive a higher VOC and a better PCE.