BAPVC Annual Project Report Project Title: Fundamental Modeling of Chalcopyrite Solar Cells

This project deals with theoretical modeling and calculation of the properties of defects in CIGS and CZTS absorber materials. The long term goal is predictive models for defect evolution, impurity kinetics and phase transformation in these materials to enable optimization of fabrication processes for maximum cell efficiency and reliability. A tool for calculation of the concentrations of dominant defects has been developed based on ab initio calculations combined with stoichiometric input data, while calculation of barrier heights leads to estimation of diffusivities. Monte Carlo simulations are used to connect these results to nanoscale ordering and impurity redistribution, with results connected to device simulation to predict impact on performance.