Additive engineering with sodium azide material for efficient carbon-based perovskite solar cells

Abstract

Perovskite solar cells with carbon electrodes (C-PSCs) are one of the low-cost and new-generation solar cell technologies to solve global energy demands. In the current research, an additive engineering approach to a perovskite precursor based on sodium azide (NaN3) material was employed to fabricate stable and efficient C-PSCs. The NaN3 additive boosted perovskite solution spreading on the SnO2 electron transport layer (ETL), resulting in a well-oriented perovskite layer with improved micro-morphology. The NaN3 additive reduced non-radiative charge recombination through the reduction of the trap density within the perovskite layer. This increased the photovoltaic performance and generated C-PSCs with a champion efficiency of 14.90%, higher than the 12.94% obtained for the unmodified C-PSCs. Indeed, the NaN3 modifier increased the JSC and fill factor (FF) parameters by reducing charge transfer resistance (Rct) and increasing charge recombination resistance (Rrec). In addition, it was observed that the NaN3-modified C-PSCs present higher shelf and ambient stability than the unmodified C-PSCs, revealing the potential of the NaN3 material for assembling efficient and stable C-PSCs.