Optically-driven gas generator by photovoltaic assisted photoelectrolysis using SE/TiO2 heterojunction structure

We propose an optically-driven gas generator on a chip by integration of a thin-film photoelectrochemical cell (PEC) and a thin-film heterojunction photovoltaic cell (PV). A Se/TiO₂ PV could supply its photo-induced open circuit voltage (V_oc) at 0.646 V as a DC bias voltage to a TiO₂-Pt PEC in order to accelerate photoelectrolysis for gas generation without external electrical sources. Integration of PEC and PV on a chip enables a compact gas generation system. Since TiO₂/ITO layers can be used as common materials for both TiO₂-Pt PEC and Se/TiO₂ PV devices, the proposed gas generator is applicable to on-chip integration. Configuration by only thin-film materials allows material-restriction-free integration of the device in terms of substrate.