The Photoelectrochemical Properties Of The Dye-sensitized Solar Cell

The conventional methods of generating electrical energy involve oil, coal and other natural resources like water, wind, tidal waves, geothermal energy. The extraordinary consumption of fossil fuels is driving to the fast depletion of natural resources and fossil fuel is the harmful effect produced on the environment due to the release of hazardous gases into the atmosphere. In order to avoid environmental pollution and future energy crisis, we must find alternative energy sources. For the environmentally friendly, inexhaustible ang so on, Solar is the most promising energy. However, the best way to use solar energy is the solar cell, in the1990s, Dye-sensitized solar cell has a new breakthrough. Due to the low cost, simple preparation process, high conversion efficiency characteristics, it has been cause the attention of people.Dye-sensitized solar cell consists of three parts, light anode (sensitized nanocrystalline semiconductors), electrolytes and electrodes. Any part has an impact on of the performance of dye-sensitized photovoltaic solar cell. In this paper, we focus on two aspects, which are the nanocrystalline semiconductor optical anode surface modification and carbon composite electrode material for electrodes, then explored the ways to improve photoelectric conversion efficiency of solar cells.(1) Mg2+1was chosen to modify the surface of the ZnO nanocrystalline electrode, which inhibited the charge recombination and increased the photoelectrical conversion efficiency of dye-sensitized solar cell. The results show that compared to unmodified ZnO nanocrystalline electrode, the short-circuit photocurrent and open circuit photovoltage of sensitized modified ZnO nanocrystals electrode significantly increased. Under the illumination of a white light of100mW·cm-2, the conversion efficiency of DSSCs is increased by44%, from5.16%to7.43%, which improved the performance of photovoltaic solar cells significantly.(2) Owing to their low cost, good electro catalytic activity, high electrical conductivity, high thermal stability and corrosion resistance, carbon materials have been intensively used as CEs and have yielded high-performance DSSCs. In this paper, Al-doped ZnO was synthesized and applied as binder to fabricate a novel mixed carbon black and Al-doped ZnO counter electrode of DSSCs. As the same method, we prepared the mixed carbon aerogel and Al-doped ZnO counter electrode of DSSCs. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to characterize the crystalline phase and morphology of the films. Photoelectrochemical experiments show that, comparable to that of the DSSCs with Pt counter electrode,the open circuit photovoltage of the DSSCs with the mixed carbon black and Al-doped ZnO counter electrode and the mixed carbon aerogel and Al-doped ZnO counter electrode increased18%(from0.694V to0.819V) and26.7%(from0.675V to0.855V), respectively. The admirable photovoltaic properties suggest that the mixed carbon black and Al-doped ZnO electrode and the mixed carbon aerogel and Al-doped ZnO counter electrode are promising alternative counter electrodes for DSSCs.