The Study Of Photovoltaic Properties And Self-sensitization About The Photoanode Of Quantum Dot-sensitized Cells

With the development of nanotechnology, inorganic semiconductor quantum-dots have gained widespread attention and become a hot topic. Quantum dot sensitized solar cells based on the dye-sensitized solar cells use quantum dots as the sensitizer. It can improve the stability problem of dye-sensitized solar cells. Theoretically, quantum dot sensitized solar cells can achieve 66% cell efficiency. However, so far, the actual efficiency of quantum dot-sensitized cells is still much lower than theoretical expectation. For this reason, it is urgent to improve the efficiency of quantum dot-sensitized solar cells.TiO2 as a general photoanode material for dye-sensitized solar cells, with the band gap(Eg) of 3.42 eV, can only absorb a small amount of UV sunlight. It is favorable to enhance the photovoltaic performance if we make the band gap narrower and the corresponding spectral range wider. Herein, we proposed a "self-sensitized" concept and annealed TiO2 film at a high temperature to introduce hydrogen to form H: TiO2 photoanode to adjust bandgap, which could enhance spectral response range.H:TiO2 photoanode, the electrolyte and the counter electrode were assembled into pure inorganic self-sensitized solar cell, and we obtained the photovoltaic converison efficiency of 0.015%.CdS has the moderate band gap(2.42eV) and good sunlight absorption in the visible region. Compared with the CdSe, CdS has higher conduction band bottom, which means the stronger electron injecting into the TiO2 conduction band and faster electron-hole pair separating speed. We prepared H:Ti O2/Cd S composite photanode and obtained the optimized conversion efficiency of 2.0% after assembling quantum dot sensitized solar cell,.