Additive-assisted passivating manipulation for printable carbon-based CsPbBr3 perovskite quantum dots solar cells with stacked structure

Carbon-based perovskite solar cells (PSCs) have attracted attention as low-cost and facile fabrication process. However, the ionic nature of perovskite and nonradiative recombination at perovskite/carbon interface are present inevitable obstacles in approaching their highly efficiency. Herein, the multifunctional molecules of zinc oxalate is implanted into the precursor of perovskite to passivate defects and narrowing the interface energy barrier, and a flexible method of screen-printing employed in prepare stacked structure device ITO/SnO 2 /CsPbBr 3 •x % ZnOX //CQDs/ITO. In this regard, CQDs are used as carbon electrodes to replace expensive materials of hole transport layer and precious metal electrode, in which CQDs extracted from sugarcane molasses, a cheap by-product of native sugar industry. Additionally, the stacked structure composed of a photoanode (ITO/SnO 2 /CsPbBr 3 •x % ZnOX) and back electrode (CQDs/ITO) exhibits a promising prospect in photovoltaic application. Finally, the power conversion efficiency of 2 % ZnOX modified PSCs increases to 1.96 %, and the improvement rate has reached 1.54 times. In addition, modified PSCs with a greater stability compared with that of the control device. This work presents a useful approach to passivate defects and provides a cost-effective option to fabricate devices with stacked structure.