Original scientific paper
Optical properties of cadmium telluride thin film in the visible and UV region
Siham Mahmoud
; Department of Electron Microscopy and Thin Films, National Research Centre, Dokki, Cairo, A. R. E.
Abdel Hamid Eid
; Department of Electron Microscopy and Thin Films, National Research Centre, Dokki, Cairo, A. R. E.
Magda Sayed
; Department of Electron Microscopy and Thin Films, National Research Centre, Dokki, Cairo, A. R. E.
Abstract
The direct transmission spectrum of cadmium telluride thin films deposited on quartz slides has been measured at room temperature (300 K). Some specimens were deposited on substrates heated up to 473 K under vacuum during film deposition. Optical transmission measurements were made over the range from 200- 900 nm for CdTe deposite having thickness of 300 to 800 nm. The values of the absorption coefficient α as a function of frequency were obtained at various thickness and substrate temperature. It is of interest to note that for different thicknesses (344-795 nm) of CdTe, the calculated absorption coefficient in the region from 1.4 to 1.6 eV on heated substrate were very close to each other. Plotting √α and α2 vs. frequency, gives the minimum energy for direct transitions (at room substrate temperature) to be 1.503 eV, and for indirect transitions 1.43 eV.
Keywords
Hrčak ID:
331788
URI
Publication date:
7.1.1991.
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