Carbon quantum dot additive engineering for efficient and stable carbon-based perovskite solar cells

Abstract Additive engineering is an effective method to manipulate formation of methyl ammonium metal halide perovskite film for high performance perovskite solar cells (PSCs). In this work, carbon quantum dots (CQDs) prepared from two different carbon sources named as A-CQDs and CA-CQDs respectively are applied as additives into CH3NH3PbI3 precursor solution in one-step processing. Film morphology and charge transport dynamics of perovskite films with different CQDs additives are investigated. It is found that the A-CQDs incorporated perovskite film has large grain size, excellent crystallinity, enhanced carrier transport ability and high hydrophobic surface. Carbon-based perovskite solar cell using A-CQDs additive shows increased cell performance with the maximum power conversion efficiency (PCE) of 13.28%. While, PCE of the PSCs modified by the CA-CQDs additive and without additive is 7.85% and 10.50% respectively. The A-CQDs additive modified PSC also presents the good long-term stability and maintains more than 90% of its initial PCE after 200 h.