Conduction mechanisms in radiation damaged MINP Si solar cells

Current-voltage characteristics of e-irradiated Si MINP solar cells were studied as a function of temperature to understand the radiation-induced enhancement in the dark current. The devices show efficiences ~ 16% and excellent junction properties before irradiation. The conduction mechanisms in as-fabricated devices have been recognized as diffusion and recombination in the space charge region through deep centers. However, current conduction was found to be dominated by the presence of shallow defect centers in the space charge layer after the devices were irradiated by 1 MeV e- to a final fluence of 1.0x1016 e-/cm2. Some of the defect level have been associated with structural damage caused by the irradiation.