Enhanced photoluminescence of a CsPbBr3/Al2O3 film heterojunction enabled by coupling of gold nanoparticles

Abstract

Abstract We studied an enhanced photoluminescence (PL) effect of CsPbBr3/Al2O3 heterojunction by using gold nanoparticls (NPs). The CsPbBr3/Al2O3 heterojunction and CsPbBr3/Au/Al2O3 heterojunction were respectively prepared on porous Al2O3 film by using a colloidal self-assembly method. The defect fluorescence of CsPbBr3/Al2O3 heterojunction was enhanced up to 40 times due to the transfer of photo-generated carriers from the CsPbBr3 quantum dots (QDs) to the porous Al2O3 film. To suppress the defect fluorescence of heterojunction, the CsPbBr3/Au/Al2O3 heterojunction was prepared by loading the gold NPs between the CsPbBr3 QDs film and the porous Al2O3 film. The results showed that the gold NPs facilitated the transfer of the photo-generated carriers from the CsPbBr3 QDs to the surface of porous Al2O3 film. Compared with the porous Al2O3 film and CsPbBr3/Al2O3 heterojunction, the peak fluorescence of CsPbBr3/Au/Al2O3 heterojunction was enhanced to 6.4 times and 2.8 times, respectively. This method of enhanced fluorescence of QD heterojunction provides a new pathway in the applications of photovoltaic, photodetector, LED, image sensor, photocatalysis.