Modeling of depletion width variation over time in thin film photovoltaics

The performance degradation of a hybrid solar cell is modelled considering the variation of depletion width over time. The p-i-n structure of a TiO₂/perovskite/HTL photovoltaic is investigated. Several different time-dependent approaches are compared and a new model is introduced based on the variation of defect density over time in depletion region. This phenomenon consequently manifests itself in the device degradation. Our approach leads to rather complicated time-dependent equation for the defect density which takes into account also the non-uniformity of electric field in the depletion region. The thickness of TiO₂ nano layer is taken 50 nm and perovskite layer is 330 nm. The nanoscale thickness of TiO₂ layer warrants the carrier transport through tunneling mechanism.