Browsing by Author "Abdi, Amensisa"

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    Optical Characterization of Thin Films for Solar Cell Application
    (Addis Ababa University, 1995-06) Abdi, Amensisa
    Reflectance (R) and Transmittance (T) measurements can provide infonnation about optical properties of thin ftlms. Optical characteristic of different transparent conducting oxides (TeOs) have been studied. Optical band gap of hydrogenated amorphous silicon and hydrogenated amorphous silicon alloys thin. films are calculated from R & T measurements using Hishikawa's relation and the program we have written. Thickness, optical band gap and dielectric function of a-Si:H films can be obtained at a time from Rand T measurements using an optical simulation soft ware for layer stacks. Near nonnal incidence R data is fitted with a model to obtain dielectric function and from the obtained result T curve is simulated to prove whether the obtained die1ecttic function represents the ftlm or not. This method can be extended even to non-transparent ftlms. To characteIize non-transparent mms, however, is necessaty to perfonn R, (s - polatized) and Rp (p - polarized) measurements for incidence angle different from near nonnal incidence (6") angle. p-i-n solar cell has been charactetizcd by the same method with a mode