V-ga Co-doped TiO₂Photovoltaic Cell Simulation And Research

Thin film solar cells are one of the most important research areas for the development of photovoltaic industry. Recently, full-inorganic oxide solar cells have attracted extensive attentions due to the tremendous advantages, such as antioxidation, long lifetime, abundant resource and non-pollution.A novel photovoltaic (PV) cell with the PIN structure was proposed based on V-Ga co-doped TiO2naterials, which have a bandgap of1.6eV obtained experimentally. A heavily doped Nb:TiO2layer is applied as the n-type layer while Cu2O or CuO were used as the p-type layer. V-Ga codoped TiO2located in the middle layer act as a main light-absorber. Built-in electric field was created between the pn junctions. The performances of the devices were simulated by AMPS-ID software. It is find that the device with three-layer Nb:TiO2/V-Ga:TiO2/Cu2O structures have better open circuit voltage, short circuit current and conversion efficience comparing with the two-layers V-Ga:TiO2/Cu2O structure. In addition, Cu2O/V-Ga:TiO2formed a II type energy band structure, which is suitable for the photovoltaic application. Simulation results shown that the photovoltaic conversion efficiency can reach34%using Cu2O as p-layer with an optimized structure. Finaly, the effect of the band tail density and the interfacial states on the performance of the PV device has been investigated. It is found that wide bandgap semiconductor used as light absorber has better internal-defect tolerance; the inserted interfacial layer produces a potential-well in the interface of conduction band and valence band and causes a mass of carrier combination, and the conversion efficiency droped from34.1%to2.6%with the interface layer inserted in.This work provides the theoretical basis for constructing V-Ga co-doped TiO2photovoltaic cells in experiment, points out the potential problems in the device fabrication progress, and gives the solutions.