Exploration of binary & ternary photosensitive thin film silver selenides: Prediction, preparation, and characterization

The solar power industry is enjoying rapid growth, but challenges remain to produce new photoactive materials with the proper balance of cost and efficiency. Much of the fundamental science concerning alternative materials has not yet been elucidated. Using ab initio density functional theory to predict band structure and densities of state for 3-D unit cells, four binary and ternary silver selenides have been identified as prime candidates for use as an absorber layer in photovoltaic cells. Thin films of these silver selenides were grown, and morphology, stoichiometry, and structure were analyzed using SEM, EDS, and XRD. Optoelectronic characterization of the films was performed using UV-Vis, Hall Effect, and photoluminescence measurements. These data were used to judge the quality of the materials and to confirm the accuracy of the predictive capability of calculations.