CD1-XZNXS FILMS FOR LOW-COST SOLAR-CELLS

Cd1-xZnxS films suitable for use in solar cells have been produced by a low cost chemical spray process. A series of technical data to make the films having uniform composition covering the range 0 to 90% ZnS concentration has been presented and the dependence of energy gap, crystal habit, X-ray and electron diffraction patterns on composition are investigated. The transition from the wurtzite structure of the zinc blende form takes place at 80 mole% ZnS concentration. The band gap has a nearly linear variation with composition except at x=1 where the material becomes amorphous and has a energy gap Eg≈3.2 eV which is smaller than that in the polycrystalline ZnS case. Doping of 5% Indium Cd1-xZnxS (x=0.1) decreases the resistivity from 104 ohm cm to Lesssim102 ohm cm which is necessary for optimum photovoltaic effciency in a Cd1-xZnxS–Cu2S solar cell. © 1979 The Japan Society of Applied Physics.