Approximation of carrier generation rate in common solar cells and studies for optimization of n+p silicon solar cell for AM1.5G and AM1.5D

This paper determines the coefficients of an empirical expression of approximated carrier generation rate in Si, Ge, GaAs, InP and Al_0.3Ga_0.7As solar cells for AM1.5G and AM1.5D spectrum to simplify the analysis of a (n⁺p) solar cell properties and offers an optimization of different parameters for silicon based solar cell. Generation rate from this expression fit closely the result obtained from PC1D software. Using the proposed carrier generation rate, an analytical model of minority carrier profile can be developed. This developed model is applied for deriving the expression of current density in the solar cell device. The emitter collection efficiency, overall conversion efficiency and the minority carrier current densities are studied for a wide range of doping concentrations (N_s = 1×10¹⁸cm^-3 to 1×10²⁰cm^-3) and emitter thicknesses (W_e = 0.1μm to 10μm); with these careful studies, a theoretical optimization of the silicon solar cell device has been made which shows good agreement with numerical analysis and previous research works.