Abstract
? 2022 Elsevier B.V.The organic-inorganic halide perovskite (OIHP) materials are becoming promising, but there is still inherent defect-mediated-carrier recombination in hybrid perovskite materials, thus, leading to inefficient power conversion efficiency (PCE). The defect states, which act as the recombination centers, are usually formed during crystallization process. Here, by a hot injection method, Na2S ligand exchange is applied to synthesize copper indium selenium quantum dots (CuInSe2 QDs), which are well dispersed in N,N-dimethylformamide (DMF) and then added into perovskite precursor solution. The resulted QD-in-perovskite structure is found to be beneficial for enlarging grain size, and thus exhibits an improved crystallinity and absorption due to the passivation of trap states. Hence, the perovskite solar cell (PSC) based on the MAPbI3-CuInSe2 QD hybrid film show an improved carrier lifetime from 58.17 ns to 243.23 ns and an enhanced PCE from 16.3% to 18.4% due to higher open-circuit voltage, compared to the cell device based on the pure perovskite film. Additionally, the optimized cell device presents better stability, which can still keep 75% of the initial PCE after 20-day storage. Such a simple Na2S ligand exchange to introduce QD into perovskite provides strong potential for preparing other hybrid materials.
NSTL
Elsevier