The interference modulated transmission spectra T( lambda ) at normal incidence for amorphous arsenic sulphide semiconducting films deposited by thermal evaporation were obtained in the spectral region from 300 nm up to 2000 nm. The straightforward analysis proposed by Swanepoel (1983), which is based on the use of the extremes of the interference fringes, has been applied in order to derive the real and imaginary parts of the complex index of refraction and also the film thickness. Thickness measurements made by a surface profiling stylus have also been carried out to cross check the results obtained by the method employing only T( lambda ). In addition, the optical band gap Egopt has been determined from the absorption coefficient values using Tauc's procedure, i.e. from the relationship alpha (h nu )=K(h nu -Egopt)2/h nu , where K is a constant. Finally, it is emphasised that accurate results were achieved not only with the above mentioned glass composition As2S3, but also in the case of the non-stoichiometric composition As30S70.

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24ev[ ~0~6 L36ev__L ____ F F E R M I Fig. 18. Derived energy band diagram for the GaAs-GaP junction at zero bias.band, E~, can then be calculated by the expressionwhere Nc is the density of states in the conduction band. Equation [5] yields a value for (EF --Ec) of 0.08 ev. This is in good agreement with conductivity measurements which give 0.07 ev for the activation energy in the GaP. Because the value of ~(1.50 ev) determined from the capacity data or current data gives the fiat band position, AEc and AEv are estimated to be 0.22 and 0.66 ev, respectively. The derived energy band diagram for the GaAs-GaP ABSTRACTThe preparation of phosphorus doped anodic oxide films on silicon is described. These oxide films can be used as phosphorus diffusion sources during heat treatment. The concentration and distribution of the phosphorus in the oxide/~lm has been investigated by tracer techniques, the quality of the oxide film by electron microscopy. Oxide growth in the solutions and at the current densities investigated occurs preponderantly by cation migration. A novel method is described for measuring the amount of silicon converted into oxide per volt forming voltage. The density of the oxide can also be calculated by this method. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 134.129.182.74 Downloaded on 2015-06-02 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 134.129.182.74 Downloaded on 2015-06-02 to IP