Performance Optimization of p-n Junction Solar cells with Device Architecture

In this paper, numerical analysis to optimize the junction depth and the total thickness of the active region in a p
⁺
-n junction silicon solar cell has been done. Recombination rate, generation rate and conduction of charge carriers inside the device are described by a system of coupled rate equations and drift-diffusion model is used for charge transport. In the analysis, several assumptions have been taken such as infinite surface recombination velocity at electrode interfaces, constant absorption coefficient and 100% quantum efficiency. The variation in the photo-generation rate of free carriers with junction depth from the front surface is included in the model. Maximum power conversion efficiency 14.7% is obtained when junction depth is 0.7 μm and device thickness is 90 μm, Variation of ideality factor shows recombination limited current is dominating for the deep junction solar cells. Short circuit current density (J
_SC
) reduces as junction depth increases which improve V
_OC
of the solar cell.