Date of Award

2001

Degree Type

Thesis

Degree Name

Bachelor of Science Honours

Faculty

Faculty of Communications, Health and Science

First Advisor

Dr Steven Hinckley

Abstract

This research project investigates the characterisation and morphology of the growth phases of polycrystalline CdS thin films that were created using the Chemical Bath Deposition (CBD) method. One batch of CdS thin films was created by the author (group B) whilst another batch (group A) was obtained from a previous research project. In both cases, the experiments were designed such that successive slides in a set represent successive phases in the growth of these CdS thin films. Therefor analysis of the near surface for all slides in a set gave an accurate representation of conditions on the surface at the corresponding time when each slide was withdrawn from the deposition bowl. These two sets of CdS thin films were then submitted to analysis using the investigative techniques of PIXE, RBS, AFM, XRD, and ESCA and notable differences were looked for. The XRD and AFM analysis was completed by the author, whilst the PIXE and RBS analysis was accomplished in conjunction with each facility manager. The ESCA analysis was achieved by the facility manager after consultation with the author. An analysis of the experimental equipment design was also carried out, resulting in a new experimental design that was built and tested. The results of the analysis highlighted a significant difference between group A and group B CdS thin films. Group A films were hard and adherent to the substrate, appearing homogeneous with good coverage and having smaller, more numerous spherical grains. However, group B films displayed an initial sulphur layer deposited on the substrate with a thicker CdS layer on top which resulted in the films being soft, powdery and not very adherent to the substrate. With group B. the CdS grains were much larger, having much rougher, non-uniform shapes indicating that the particulate phase was dominant during its formation.

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