Growth analysis of cadmium sulfide thin films by atomic force microscopy

Abstract

CdS films have been deposited by solution growth on SnO/sub 2/ and glass substrates. Nucleation on SnO/sub 2/ occurs at early deposition times, and complete conformal coverage is observed at low thickness values. The average grain size of the CdS films is established at these early times. In films deposited on glass substrates, nucleation is slower and occurs through 3-dimensional islands that increase in size and number as deposition proceeds. Optical measurements show that the bandgap values of CdS films deposited on SnO/sub 2/ depend mainly on substrate structure. Hydrogen heat treatment does not affect the surface morphology of the samples, but decreases bandgap values.