Photoelectrochemical characterization of CuGaSe/sub 2/ and Cu(Ga,In)Se/sub 2/ films and defect chemical implications for solar cell performance

Abstract

The effective electronic parameters and the optical bandgap of CuGaSe/sub 2/ and Cu(Ga,In)Se/sub 2/ films were determined by using an organic liquid electrolyte to form a Schottky barrier to the films. Trends in the electronic parameters, composition, and additional information were used in a defect chemical framework to explore the effects of Ga substitution/doping on CuInSe/sub 2/. Values for optical and (effective) electronic parameters for several CuGaSe/sub 2/ films are reported. Photocurrent-wavelength data are also shown. In CuGaSe/sub 2/ (as in CuInSe/sub 2/), film stoichiometry needs to be reasonably well controlled, close to Cu/Ga=1, according to the results.<>