Γ‐Ga2O3 Nanocrystals Electron‐Transporting Layer for High‐Performance Perovskite Solar Cells. Issue 9 (11th July 2019) - Hu, Ke-Hao
Abstract : The electron‐transporting layer (ETL) plays a very important role in perovskite solar cells (PSCs). The traditional TiO2 ETL exhibits drawbacks such as complex preparation process and low stability. Devices incorporating TiO2 as the ETL also show large hysteresis that limits their performance. Herein, Ga2 O3 nanocrystals (NCs), prepared by a solution process, are applied as an ETL in n‐i‐p planar structured PSCs. The Ga2 O3 ‐based devices exhibit negligible hysteresis and achieve higher performance than the TiO2 ‐based devices. Due to better energy level matching and smoother surface morphology, films of Ga2 O3 NCs make good interfacial contact with the perovskite top layer, improving the charge transport efficiency. The perovskite layer also exhibits high crystallinity. Unlike TiO2, which is commonly prepared by high‐temperature sintering or solution hydrolysis, films of Ga2 O3 NCs can be prepared by solution spin‐coating at a low temperature. This greatly reduces the complexity of fabrication and improves device performance. Abstract : Solution‐processable Ga2 O3 nanocrystals are developed as a novel electron‐transporting layer for high‐performance perovskite solar cells. The smooth film of Ga2 O3 nanocrystals offers a better interface with perovskite and improves charge transport efficiency. The Ga2 O3 ‐based device shows negligible hysteresis unlike the TiO2 ‐based analogue.