Fabrication and characterization of Cu(In,Ga)Se2 thin-film solar cells prepared via a solution process

Cu(In,Ga)Se₂ films with a chalcopyrite structure have been successfully synthesized via a solution process in this study. Well-crystallized Cu(In,Ga)Se₂ films were obtained after selenization in a tube furnace. The prepared films were characterized via X-ray diffraction and scanning electron microscopy analysis. The current-voltage characteristics of the Cu(In,Ga)Se₂ solar cells were measured under AM 1.5 global spectrum. The Cu/(Ga+In) ratios affected the crystallinity, morphology and grain size of the prepared films. It was also found that the compositions of the prepared films had great influence on the efficiency of the solar cells. In addition, the effects of selenization temperatures and duration on the morphology were discussed. Increasing the selenization temperature and duration led to the enhancement of the grain size and crystallinity of the Cu(In,Ga)Se₂ films.