Chalcopyrite thin film solar cells by electrodeposition

This paper reviews the state of the art in using electrodeposition to prepare chalcopyrite absorber layers in thin film solar cells. Most of the studies deal with the direct preparation of Cu(In,Ga)Sc₂ films, and show that the introduction of gallium in the films is now becoming possible from single bath containing all the elements. Electrodeposition can also be used to form precursor films with stacked layer structures, of pure elements or of combinations with binary or even ternary films. Thermal annealing treatments are of dramatic importance to provide suitable electronic quality to the layers. They are often done in the presence of a chalcogen (selenium or sulfur) over pressure and there is a tendency to use rapid thermal processes. Less studies are devoted to complete solar cell formation. Significant progresses have been made in the recent period with several groups achieving cell efficiencies around 8-10% on different substrates. A record efficiency of 11.3% is reported for a cell with an absorber presenting a band gap of 1.47eV. First results on the manufacturability of the corresponding process to large areas are presented.