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

Abstract

We studied an enhanced photoluminescence (PL) effect of CsPbBr _3 /Al _2 O _3 heterojunction by using gold nanoparticls (NPs). The CsPbBr _3 /Al _2 O _3 heterojunction and CsPbBr _3 /Au/Al _2 O _3 heterojunction were respectively prepared on porous Al _2 O _3 film by using a colloidal self-assembly method. The defect fluorescence of CsPbBr _3 /Al _2 O _3 heterojunction was enhanced up to 40 times due to the transfer of photo-generated carriers from the CsPbBr _3 quantum dots (QDs) to the porous Al _2 O _3 film. To suppress the defect fluorescence of heterojunction, the CsPbBr _3 /Au/Al _2 O _3 heterojunction was prepared by loading the gold NPs between the CsPbBr _3 QDs film and the porous Al _2 O _3 film. The results showed that the gold NPs facilitated the transfer of the photo-generated carriers from the CsPbBr _3 QDs to the surface of porous Al _2 O _3 film. Compared with the porous Al _2 O _3 film and CsPbBr _3 /Al _2 O _3 heterojunction, the peak fluorescence of CsPbBr _3 /Au/Al _2 O _3 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.

Keywords

• surface enhanced fluorescence
• quantum dot heterojunction
• porous Al2O3 film
• CsPbBr3 quantum dot
• gold nanoparteilces (NPs)