DefinePK

Abstract

Thin films of PbBr2 were synthesized on glass substrate by Physical Vapor Deposition (PVD) and thin films of CsPbBr3 were synthesized by Dip Coating Method of a film of PbBr2 in a solution of CsBr in methanol. The crystalline system corresponding to CsPbBr3 was identified crystallographically by X-ray diffraction and the desired stoichiometry was found from a three-dip test with a film anneal time at 100 0 C for a time of 20 minutes. The morphology of the PbBr2 and CsPbBr3 films was studied by scanning electron microscopy (SEM), the structural change and the variation in grain size were analyzed as a function of the annealing temperature and the formation of CsPbBr3, an increase was observed in the grain size after the annealing of the PbBr2 film and subsequently in the formation of CsPbBr3. Finally, the optical properties of the material were evaluated by optical reflectance measurements and an optical band gap of 2.31 eV and absorption coefficients of 6x104 cm-1 were obtained for the fundamental absorption and 5x104 cm-1 for the near ultraviolet. The band gap of the material was also determined using the band structure diagram obtained from Heyd-Scuseria-Ernzerhof (HSE) density functionalities and a value of 2.30 eV was obtained.