Influence of SiO2 Nanoparticles on the Structural, Morphological, and Optical Properties of CsPbBr3 Quantum Dots

Shymaa K. Hussian; Majid R. Al-bahrani

doi:10.37591/jopc.v11i2.7467

Abstract

This work mainly investigates the structural and optical property differences between CsPbBr3/SiO2 quantum dots (QDs) and CsPbBr3 QDs thin films deposited on fluorine-doped tin oxide (FTO) glass. X-ray diffraction of CsPbBr3/SiO2 QD thin film showed a polycrystalline cubic nanostructure with (200) as a dominant phase and did not show any peak of SiO2. Scanning and transmission electron microscopy images show that it is very small spherical or semi-spherical particles with a regular distribution within the dimensions of the quantum that they have different directions, also indicating that CsPbBr3/SiO2 QD coexisted in the samples reducing the overall size. In addition, the particle sizes (diameters) were decreased from 2 to 4 nm. The optical band gap values for CsPbBr3 and CsPbBr3/SiO2 QDs ranged from 2.41 to 2.38 eV due to the formation of nano-sized CsPbBr3/SiO2 particles, which have a large optical absorption coefficient in the visible band. The CsPbBr3 QDs always have a wider band gap than that of CsPbBr3/SiO2 QDs, because the quantum size effect makes the smaller QDs have a larger bandgap.