Optical Properties of CdTe Thin Films

The optical constants (the refractive index n and the absorption constant K) and absorption coefficients x are measured on CdTe thin films in the wavelength range 500 to 2000 nm. Some parameters which affect these optical properties of thin films, such as the film thickness, substrate temperature, doping with impurities like In, BaF2, PbCI2 are also investigated. Effective crystallite size and strain are determined by the method of variance analysis of the X-ray diffraction line profiles on the same films. It is observed that there is an increase in optical band gap with decrease in crystallite size and increase in strain. Die optischen Konstanten (der Brechungsindex n und die Absorptionskonstante K) und der Absorptionskoeffizient x werden in dunnen CdTe-Schichten im Wellenlangenbereich von 500 bis 2000 nm gemessen. Einige Parameter, die diese optischen Eigenschaften dunner Schichten beeinflussen, wie Schichtdieke, Substrattemperatur, Dotierung mit Storstellen wie In, BaF2, PbCI2 werden ebenfalls untersucht. Effective Kristallitgrose und Spannung werden mit der Metbode der Varianzanalyse der Rontgenbeugungslinienprofile an denselben Schichten bestimmt. Es wird beobachtet, das ein Anstieg der optischen Bandlueke mit sinkender Kristallgrose und Anwachsen der Spannung auftritt.

[1]  J. Lewis.  Optical Properties of the Alloy System SnTeGeTe from Reflectance Measurements , 1987 .

[2]  S. Chaudhuri,et al.  Optical transitions in CdTe thin films produced by hot- wall vacuum evaporation , 1987 .

[3]  J. Mercier,et al.  Formation, microstructure et résistances des contacts AuGe/n-GaAs, AuGe/n-InP, AuZn/p-InP et AuBe/p-InP , 1985 .

[4]  T. Ohshima,et al.  Preparation of CdTe thin films on Ge substrates by molecular beam epitaxy , 1985 .

[5]  T. C. Anthony,et al.  Growth of CdTe films by close‐spaced vapor transport , 1984 .

[6]  D. K. Reinhard,et al.  Hydrogenation effects in sputtered polycrystalline cadmium telluride , 1984 .

[7]  K. Uosaki,et al.  Composition and electronic properties of electrochemically deposited CdTe films , 1984 .

[8]  S. Gogoi,et al.  D.C. electrical properties of vacuum-deposited CdTe films , 1982 .

[9]  T. V. Doren,et al.  Photoluminescence in spray-pyrolyzed CdTe , 1981 .

[10]  A. A. El-Shazly,et al.  Some parameters affecting the optical constants of CdTe thin evaporated films , 1981 .

[11]  J. P. Fillard,et al.  Optical and electrical properties of SnO2 thin films in relation to their stoichiometric deviation and their crystalline structure , 1977 .

[12]  M. Rodot.  Materials for solar photocells :Place of CdTe , 1977 .

[13]  E. E. Khawaja,et al.  The optical constants of thin evaporated films of cadmium and zinc sulphides , 1975 .

[14]  I. Filiński,et al.  The effects of sample imperfections on optical spectra , 1972 .

[15]  John D. Dow,et al.  Electroabsorption in Semiconductors: The Excitonic Absorption Edge , 1970 .

[16]  D. Redfield,et al.  THE DIRECT ABSORPTION EDGE IN COVALENT SOLIDS , 1967 .

[17]  D. Marple,et al.  Optical Absorption Edge in CdTe: Experimental , 1966 .

[18]  B. Segall.  Optical Absorption Edge in CdTe: Theoretical , 1966 .

[19]  Marvin L. Cohen,et al.  Band Structures and Pseudopotential Form Factors for Fourteen Semiconductors of the Diamond and Zinc-blende Structures , 1966 .

[20]  T. S. Shilliday,et al.  Some Optical Properties of Cadmium Telluride , 1960 .

[21]  J. Loferski,et al.  Theoretical Considerations Governing the Choice of the Optimum Semiconductor for Photovoltaic Solar Energy Conversion , 1956 .

[22]  D. Riley,et al.  An experimental investigation of extrapolation methods in the derivation of accurate unit-cell dimensions of crystals , 1945 .