Characterization of Al/SiO2/arbitrarily-doped pp+-Si solar cell

Al/SiO₂/pp⁺-Si metal-insulator-semiconductor (MIS) solar cell device was simulated using a comprehensive numerical model. The semiconductor layer consists of p-type Si epitaxial layer (base) which is deposited on p⁺-Si(001) substrate. The doping profile in the base layer was chosen to be arbitrary with different doping gradients. The effect of doping profile in the base layer and substrate was studied. The built-in electric filed, generated due to inhomogeneous doping in the base layer, extends deeply inside the base layer as the doping gradient is increased. The performance of the device as a solar cell was optimized at a doping gradient of 5×10⁴ cm^-1 and a substrate doping density of 1×10¹⁷ cm^-3. The simulation results suggest that MIS solar cells performance can be improved by the inhomogeneous impurity distribution inside the base layer.