Specific features of the recombination loss of the photocurrent in $n$-TiN/$p$-Si anisotype heterojunctions

Photosensitive $n$-TiN/$p$-Si heterostructures are fabricated by reactive magnetron sputtering. The heterostructures generate an open-circuit voltage of $V_{\mathrm{oc}}$ = 0.4 V and a short-circuit current of $I_{\mathrm{sc}}$ = 1.36 mA/cm$^2$ under illumination at 80 mW/cm$^2$. An analysis of the light current-voltage characteristic and quantum-yield spectrum demonstrate that the poor photoelectric parameters are due to recombination in the base region of the heterojunction and to the formation of a high-resistivity SiO$_2$ layer on the surface of polycrystalline silicon, which fails to provide high-quality passivation of surface states.