Hole transport free carbon-based high thermal stability CsPbI 1.2 Br 1.8 solar cells with an amorphous InGaZnO 4 electron transport layer.

Due to their low cost, tunable band gap and excellent thermostability, all-inorganic halide perovskites CsPbX 3 (X = Br, I) have become a kind of promising photovoltaic material. However, compared to the organic-inorganic hybrid perovskite solar cells, the performance of CsPbX 3 solar cells still needs to be improved. In this work, for the first time, we applied the sol-gel derived amorphous InGaZnO 4 film as electron transport layers (ETLs) in CsPbX 3 -based devices. In these devices, the carbon electrode deposited by screen printing replaced the unstable hole transport layer and the expensive metal electrode to obtain hole transport free carbon-based devices, which significantly simplifies the preparation process and reduces the production cost. With the application of amorphous InGaZnO 4 films, devices show a relatively high power conversion efficiency (9.07%) and excellent thermal stability. Compared with the reported CsPbX 3 devices using SnO 2 or TiO 2 ETLs, the performance of amorphous InGaZnO 4 based devices has been significantly improved. This work provides a promising route to prepare highly thermally stable all-inorganic perovskite solar cells using a-IGZO films.