Transformation of the structural surface morphology and electronic structure of CdS nanostructured films prepared in glycerol-containing solution, under ultrasonic irradiation

Trung Tran, Duc Tung Ngo, Thi Huong Vu, Thi Dong Nguyen and Chang-Sik Ha

Abstract

Chemical bath deposition was improved by using glycerol, a very conventional surfactant, to control cadmium sulfide CdS in various sizes and structures, under ultrasonic irradiation conditions. Consequently, an effective route to prepare CdS thin film that consists of either CdS fibrils with an average diameter of 52 nm or monodispersed CdS grains 35 to 80 nm in size is proposed. X-ray diffraction (XRD) studies revealed that, in the crystallographic properties of the obtained CdS films, CdS may exist in two crystalline modifications—a hexagonal and a cubic phase—that are characterized by several diffraction peaks positioned at 2θ≈23.4°, 27.1° and 47.8°. Beside this, UV-Vis studies also revealed the positive effect of glycerol at grain boundaries, leading to detrimental reduction of the band bending towards the absorber surface and increasing the population of optical absorptions