Recent progress in thin‐film cadmium telluride solar cells

Abstract

Abstract Cadmium telluride (CdTe) with a room‐temperature bandgap energy of 1.45 eV has been shown to be the most promising low‐cost, thin‐film photovoltaic material for terrestrial applications. Significant progress has been made during the past several years, and thin‐film CdTe solar cells of > 1 cm 2 area with conversion efficiencies higher than 12% have been prepared by several techniques. Thin‐film CdTe photovoltaic modules with 10% efficiency have also been produced. They are of the heterojuntion configuration using a transparent conducting semiconductor (TCS) as the window and p‐CdTe as the absorber. In this paper, the potential window materials for thin‐film CdTe solar cells are discussed. Thus far, cadmium sulphide (CdS) with a bandgap energy of 2.42 eV at room temperature has been found to be best suited for efficient CdTe solar cells. the deposition techniques for p‐CdTe films capable of producing efficient solar cells, including close‐spaced sublimation (CSS), electrodeposition, screen printing and spraying, are briefly reviewed, and the characteristics of the resulting solar cells are discussed. It is concluded that the efficiency of thin‐film CdTe solar cells can be increased to 18‐19% in the near‐term, leading to 15‐16.5% efficient modules.