 The addition of NH for CL and SNCL to Bullet Operator 2H20 to a SNO2-based electron transport layer, ETL, significantly improved the performance of perovskite solar cells under thermal and light stress conditions. The modification resulted in increased stability of the device, with an efficiency retention rate of over 80%. This article was authored by Bum Jean Gill, Alan Jeevan Yuen, Jihee and Lim, and others.