A Study of The Physical Properties of Some Materials For Use In Solar Cell Devices

Abstract

A brief review of solar cell technologies is presented, high lighting the development and potential of the thin film polycrystalline devices in particular those based on the ternary chalcopyrite CulnSe2 . Current knowledge of the properties of CdS & CulnSe2 and thin film deposition techniques for the two materials is summarized. Two methods of preparation CdS have been studied. The first is thennal evaporation on cold substrate followed by thermal annealing at different temperature .• Results from various thin film analysis techniques show that it is possible to prepare stoichiometric CdS film not only on hot substrate but even if it is cold. The effects of mmealing process on the film compositions, optical and electrical properties are delineated . • The second technique of preparing CdS films is the solution growth SG teclmique . pH value , duration time and temperature effects on physical properties of prepared films are studied. Structure of the films was examined by x-ray diffraction . Energy band gap for films deposited by the two techniques calculated from transmittance measurements, it was 2.42 eV which assistant with literature. The deposition of a stack of elemental layers was found to produce large area . good quality CulnSe2 films after processing in air. Results presented in this work show that the compound with the preferential chalcopyrite structure can be formed after annealing at temperature more than 300 °C . Film properties are dependent on annealing conditions and film composition. Composition can be easily controlled by variation of the as- deposited elemental thickness. Conclusions drawn from this work indicate that: I) CdS films can be produced by methods more simple & economic than the familiar ones. 2) The stacked elemental layers (SEL) technique is highly promising for the commercialization of CulnSe2 devices.