Date of Award

1-1-2000

Thesis Type

Masters

Document Type

Thesis

Divisions

Faculty of Science

Department

Department of Chemistry

Institution

Universiti Malaya

Abstract

Hydrogenated amorphous silicon (a-Si :H) films were prepared from the discharge of pure silane and silane diluted in argon using a home-built hori zontal direct current(d.c.) plasma glow discharge system. The effects of argon dilution of silane on the optical properties, chemical bonding properties, hydrogen content and microstructure parameter of the films produced were studied and analyzed. Film thickness, refractive index, optical energy gap and the Urbach tail bandwidth were obtained from the optical transmission spectra of the films while the H content and the microstructure parameter were derived from the Fourier Transform infra-red(FTIR) spectra of the films. The FTIR spectra also provided information on the chemical-bonding properties, purity and homogeneity of the film structure. Results showed that these properties were dependent on the argon to silane flow-rate ratio in most cases. High argon dilution had the effects of decreasing the refractive index of the film and indirectly the bulk density of the film, the microstructure content as well as the total hydrogen content of the a-Si:H film. Film homogeneity also increased in the higher argon diluted film . Low argon dilution resulted in increase in the deposition rate but high argon dilution (argon to silane flow-rate ratio larger or equal to one), resulted in retardation in the growth rate. High deposition rate films had low refractive index, low hydrogen content, less disordered structure and high amount of microstructure. The deposition rate, however showed no significant influence on the optical energy gap of the films.

Initial

snms

Additional Information

Dissertation (M.A) -- Faculty of Science, Universiti Malaya, 2000.

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