Analysis of the series resistance in pin-type thin-film silicon solar cells

The series resistance of microcrystalline hydrogenated silicon thin-film pin-type solar cells is investigated using illumination dependent current/voltage characteristics. We present a simple analytical model describing the total series resistance of low-mobility pin-type solar cells. The model thus provides insight into the influence of the material properties of the intrinsic layer on the series resistance. Our model allows us to separate the voltage dependent internal resistance of the intrinsic layer from the residual, external resistance. We verified our model over a wide range of parameters relevant to thin-film silicon devices by comparison to numerical simulations. Finally, we demonstrate that our model can consistently describe the series resistance of experimental a μc-Si:H pin-type solar cell. Furthermore, the fitting of the model with experimental data yields the external series resistance and information of the carrier mobilities and effective density of states in the bands of the intrinsic layer in the device.