Supplementary material

The schematic diagram and AFM image of p-GaN substrate; the cubic structure, TEM image and AFM image of CsPbBr3 perovskite QDs; side view, top view and fatbandstructure of CsPbBr3/GaN heterojunction; energy band diagram of CsPbBr3 and energy band diagram of GaN; heterojunction electron localization function; the function diagram of absorption coefficient and light energy of isolated GaN, CsPbBr3 and CsPbBr3/GaN heterojunction.

p-GaN衬底的示意图及原子力显微镜（AFM）图像；CsPbBr3钙钛矿量子点的立方结构、透射电子显微镜（TEM）图像及AFM图像；CsPbBr3/GaN异质结的侧面视图、顶视图和肥带结构；CsPbBr3与GaN的能量带图；异质结电子局域化函数；孤立GaN、CsPbBr3及CsPbBr3/GaN异质结的吸收系数与光能量的功能图。