Surface passivation of polycrystalline, chalcogenide based photovoltaic cells

We present a summary of our defect chemical microscopic model for the effect that annealing in air or oxygen has on CuInSe₂ and CdTe-based polycrystalline thin film solar cells and explain its generalization to other chalcogenide-based semiconductor devices. The summary includes a hypothesis for specific O₂ (molecule) and surface interaction. From the point of view of device performance, the model provides a specific chemical explanation for the conclusions obtained from device analyses that the performance of the present generation of polycrystalline cells of this type is mainly limited by recombination at grain surfaces and boundaries.