Photocarrier radiometry for noncontact evaluation of space monocrystalline silicon solar cell under low-energy electron irradiation

A space monocrystalline silicon (c-Si) solar cell under low-energy (< 1 MeV) electron irradiation was investigated using noncontact photocarrier radiometry (PCR). Monte Carlo simulation (MCS) was employed to characterize the effect of different energy electron irradiation on the c-Si solar cell. The carrier transport parameters (carrier lifetime, diffusion coefficient, and surface recombination velocities) were obtained by best fitting the experimental results with a theoretical one-dimensional two-layer PCR model. The results showed that the increase of the irradiation electron energy caused a large reduction of the carrier lifetime and diffusion length. Furthermore, the rear surface recombination velocity of the Si:p base of the solar cell at the irradiation electron energy of 1 MeV was dramatically enhanced due to 1 MeV electron passing through the whole cell. Short-circuit current (I_sc) degradation evaluated by PCR was in good agreement with that obtained by electrical measurement.