Photovoltaic Behaviors in an Isotype n-TiO₂/n-Si Heterojunction

An n-TiO₂/n−Si isotype heterojunction is fabricated by depositing TiO₂ thin films onto n−Si substrates. Obvious photovoltaic behaviors are observed in this isotype heterojunction. The open circuit voltage and short circuit current of the heterojunction can reach 123 mV and 20 µA/cm², respectively. The mechanism for the photovoltaic behaviors can be understood in terms of the band alignment of the heterojunction. The results reported may provide a feasible route to easily available and low-cost isotyped photovoltaic devices.