Enhanced aqueous stability and radiative-charge-transfer of CsPbBr3/Ag2S perovskite nanocrystal hybrids

Abstract A convenient strategy to enhance the aqueous stability and radiative-charge-transfer of perovskite nanocrystals (PNCs) is developed via hybriding CsPbBr3 PNCs with Ag2S nanoparticles, which is conducted by directly decomposing silver diethyldithiocarbamate in CsPbBr3 PNCs crude. The obtained CsPbBr3-Ag2S hybrids are aqueous stable, and exhibit obviously enhanced aqueous photoluminescence (PL) with a quantum yield up to 82% in pure water as well as boosted electrochemical response for charge injection and 9-fold enhanced electrochemiluminescence (ECL) than CsPbBr3 PNCs in aqueous electrolyte. Both PL and ECL spectra of CsPbBr3-Ag2S hybrids are almost identical to the PL spectrum of CsPbBr3 PNCs, indicating radiative-charge-transfer within CsPbBr3-Ag2S hybrids only occurs in CsPbBr3 segment. Annihilation ECL demonstrates that all the charges injected onto CsPbBr3-Ag2S hybrids at the redox potentials of Ag2S segment can be efficiently transferred into CsPbBr3 segment to enhance radiative-charge-transfer. This strategy is promising for the application of PNCs as well as the developing of novel electrochemiluminophores.