Abstract
Effects of annealing on the properties of boron-doped CdS films prepared by chemical bath deposition using boric acid as a dopant source were investigated. The crystalline orientation and the grain size of CdS films appeared to be seriously affected by the annealing ambient. The crystal structures of H2-annealed films were wurtzite type with a preferential orientation of the (002) plane and the grain size slightly increased. For samples annealed in N2 and air, however, the preferential orientation of the (002) plane disappeared or decreased and the grain size was identical to or smaller than that for H2 ambient. The dark resistivity decreased by annealing in H2 and increased further with increasing annealing temperature. For N2 and air ambient, the dark resistivity was larger than that of the H2-annealed films and the optical transmittance was less than that of the H2-annealed films. These results suggest that annealing in H2 ambient is suitable for photovoltaic device application.