Enhanced charge extraction enabled by amide-functionalized carbon quantum dots modifier for efficient carbon-based perovskite solar cells.

[Display omitted] • Low edge defects of CQDs induced by MBA functionalization improve carrier transport. • The MBA/CQDs with high healing effect holistically passivate the defects of PVK film. • The deeper HOMO of MBA/CQDs reduces energy barrier for increased hole extraction. • The unsealed device achieves a best PCE of 10.40% and high humidity-heat stability. The effective improvement of interfacial charge extraction and inhibition of charge recombination are crucial for promoting the performance of perovskite (PVK) solar cells (PSCs). Here, the N,N'-methylenebisacrylamide-functionalized carbon quantum dots (MBA/CQDs) with defects passivation effect and appropriate energy levels are proposed as a back interface modifier for carbon-based CsPbBr 3 PSCs. The functionalization of MBA molecules not only increases the content of sp 2 hybrid carbon in CQDs, but also expands the passivation effect of CQDs on surface defects of PVK films by introducing carbonyl and amino groups, which improves the carrier transport and reduces the carrier nonradiative recombination. Additionally, the modification of MBA/CQDs provides an intermediate energy level at the PVK/carbon back interface, which boosts hole extraction and lowers energy loss. Finally, a leading-edge power conversion efficiency of 10.40 % is derived for the MBA/CQDs modified champion device, which is significantly improved compared to the 7.02 % efficiency for the original CsPbBr 3 PSCs. Furthermore, the unpackaged CsPbBr 3 PSCs with MBA/CQDs have an excellent stability, maintaining an initial efficiency of 92 % after 30 days of storage at high humidity (85 % relative humidity) and temperature (85 °C) in air. [ABSTRACT FROM AUTHOR]