One step electrodeposition of CuInSe₂: Improved structural, electronic, and photovoltaic properties by annealing under high selenium pressure

Films of Cu-In-Se alloys can be electrodeposited in a wide range of controlled composition. Annealing treatments under Se pressure transform these precursor films in large grain CuInSe₂ films with improved electronic properties. These modifications are shown to depend on the Se pressure imposed during the treatment allowing a certain tailoring of the electronic properties of the films. The properties of electrodeposited/selenized films are presented as obtained from luminescence measurements, Hall effect, and photoelectrochemical characterization. An efficiency of 6.5% (total area, without antireflecting coating) is reported for the best CuInSe₂/CdS/ZnO solar cell. An analysis of the device is also presented where limitations by interface recombination are shown to be the dominant loss mechanism.