Confining halide perovskite crystals CH3NH3PbBr3 in porous aluminum oxide thin film

In this work, the photoluminescence emission properties of CH3NH3PbBr3 perovskite crystals which encapsulated among the porous thin films of aluminum oxide are studied. These porous layers are made by electrochemical anodizing method. First, aluminum thin film has been deposited by magnetron sputtering deposition method and then by changing anodic voltage, different patterns of porous aluminum oxide films are fabricated. Finally, CH3NH3PbBr3 nanocrystals are synthesized on the Al2O3 porous thin film by one step spin coating method. Morphological studies of porousaluminum oxide thin films are investigated by field emission scanning electron microscopy images and Atomic Force Microscope results. In order to study optical response of  CH3NH3PbBr3 erovskite pto structural characteristics of  porousthin films, photoluminescence spectroscopy has been employed too. By structural characterization, it is found that the number and the average diameter of the nano-pores are increased by anodic voltage raising. Also, the dependence of the emission properties of the encapsulated crystals on the size of the pores has been determined by the photoluminescence spectroscopy. So that, blue-shifted photoluminescence emission has been observed by the pores diameter reduction. Eventually, by comparing the results of structural and optical characterizations with Bruce model, the fabrication of  CH3NH3PbBr3 perovskite nanocrystals within the patterned aluminum oxide mold is confirmed.