Radiation resistance of $\alpha$-Si:H/Si heterojunction solar cells with a thin $i$-$\alpha$-Si:H inner layer

We have studied the degradation of photoelectric characteristics of heterojunction solar cell samples based on $\alpha$-Si:H/Si structures upon irradiation by electrons with an energy of 3.8 MeV and fluences of 1 $\times$ 10$^{12}$–1 $\times$ 10$^{14}$ cm$^{-2}$. It is shown that the efficiency of the samples of heterojunction solar cell elements under the conditions of AM0 illumination (0.136 W/cm$^2$) is reduced by 25% at a fluence of 2 $\times$ 10$^{13}$ cm$^{-2}$. This is more than an order of magnitude higher than the critical fluence value achieved previously when silicon solar cells with a $p$–$n$ junction and an $n$-type base were irradiated by high-energy electrons.