Enhanced Light Absorption in Textured Metal Organic Chemical Vapour Deposited (MOCVD) CdO Thin Films

摘要

The Single Solid Source precursor Cadmium Acetylacetonate, Cd[C_5H_7O_2]_2 was prepared and Cadmium Oxide thin films were deposited on Sodalime glass substrate using Metal Organic Chemical Vapour Deposition (MOCVD) technique at deposition temperature of 420 ℃ The films were characterized using Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray (EDX) facility attached to it, X-Ray Diffractometry (XRD) and UV-visible spectrometry. SEM micrographs showed the formation of textured surface with identifiable cubic and hexagonal structures, having average grain size greater than 1 urn. XRD studies indicated the formation of polycrystalline cubic CdO phase with preferred orientation in (111) plane. A direct optical band gap of 2.10 eV was obtained from the analysis of the UV-visible spectrum with an enhanced light absorption in 750 - 1000 nm spectrum range. This enhancement is as a result of light trapping by the textured crystalline structure.