Huafei Guo

Theoretical and experimental study on the optical and electrical properties of Cu2ZnTiS4 and its photovoltaic applications

In this paper, a I2-II-IV-VI4 quaternary kesterite-structured semiconductor Cu2ZnTiS4 thin film is synthesized by a co-sputtering approach. Its structural properties are investigated via various experimental techniques combining the prediction from first-principle calculations. Stable chemical potential range is analyzed according to the formation energy of Cu2ZnTiS4 and its competing phases. The results show that the stable pure Cu2ZnTiS4 phase can exist and the most possible impure phases are ZnS and Cu2TiS3. X-ray diffraction analysis reveals the cubic crystal structure, which is expected in the calculations. Raman spectrum analysis excludes the possibility of ZnS and Cu2TiS3 phases, which corroborates the formation of single Cu2ZnTiS4 phase. The Cu2ZnTiS4 thin film exhibits dense and pinhole free surface morphologies and a bandgap of 1.42 eV is observed. The initial photovoltaic device based on this material exhibits a 0.83% efficiency. These findings offer a promising candidate material for quaternar...