Improved radiation resistant properties of electron irradiated c-Si solar cells

This work investigates the radiation tolerance of c-Si solar cells under electron energy of 9 MeV with fluence of 5.09×1016 cm⁻²_. The solar cells were fabricated and characterized before and after electron irradiation through current-voltage (I-V), capacitance-voltage (C-V), and frequency dependent conductance (G_p) measurements. The results revealed that all the output parameters such as short circuit current (I_sc), open circuit voltage (V_oc), series resistance (R_s), and efficiency (η) were degraded after electron irradiation. Capacitance-Voltage measurements show that there is a slight decrease in the base carrier concentration (N_D), while a small increase in depletion layer width (W_D) was due to an increase in the base carrier concentration. Enhancements in the density of interface states (N_ss), and trap time constant (τ) have been observed after electron irradiation. The results has revealed that back surface field (BSF) solar cell with front surface passivation (FSP) presented lowest efficiency degradation ratio of 11.3% as compared to 15.3% of the solar cell without FSP. The subsequent annealing of irradiated Si solar cell devices revealed that the Si solar cell with FSP demonstrated high efficiency recovery ratio of 94% as compared to non-FSP solar cell. - Highlights: • c-Si solar cells were fabricated and subjected to 9 MeV electron radiation. • I-V measurements of pre and post irradiated and annealed solar cells. • Capacitance and conductance characteristics were done before and after irradiation. • Increase in density of interface states and trap time constant after irradiation. • FSP solar cell showed lower degradation and higher efficiency recovery ratios.