Carbon quantum dots passivated CsPbBr3 film with improved water stability and photocurrent: Preparation, characterization and application

摘要

All-inorganic cesium lead perovskite quantum dots (PQDs) with excellent optical properties have obtained extensive study in the field of optoelectronics. However, the poor stability of CsPbBr3 in the atmosphere and water severely limits their practical application. In this work, carbon quantum dots (CQDs) were exploited as dopants to improve the aqueous stability and photo-induced charge transfer properties of CsPbBr3. A highly fluorescent and aqueous stable film, consisting of CQDs-CsPbBr3 embedded in polyvinylidene fluoride (PVDF) polymer, was obtained by a simple spin coating method. Experiment results showed that the fluorescence (FL) intensity of CQDs-CsPbBr3@PVDF film retained about 85% of its initial value after being soaked in water for 50 days, indicating the good water stability of CQDs doped CsPbBr3. Besides, the photocurrent of CsPbBr3 film increased from 0.1 mu A to 0.9 mu A after doping CQDs under light irradiation, which proved that the improved charge transfer of CsPbBr3 was beneficial from CQDs. The application of CQDs-CsPbBr3@PVDF film in down-converted light emitting diodes has also been checked. This work highlighted one application of CQDs for improving the performances of PQDs in the field of optoelectronics. (C) 2021 Elsevier Ltd. All rights reserved.