纳米TiO_2的表面修饰及其光电性能

Surface Modification of Nanometer Particles of TiO_2 and Its Photovoltaic Performance

研究了表面修饰对TiO2光阳极微结构和光电性能的影响。结果表明,在纳米TiO2颗粒表面涂敷一层适当厚度的WO3阻挡层能够有效抑制光生电子与电解质中的阳离子或氧化态的染料分子之间的复合,从而提高了染料敏化太阳能电池的开路电压、短路电流和光电转换效率。但过厚的WO3阻挡层虽能抑制电荷复合,也阻碍了电子注入过程,不利于电池转换效率的提高。

The effect of surface modification of TiO2 nano-particles on the microstructure of titania photoandode and the photovoltaie characteristics of dye-sensitized solar cells was studied. The results indicated that an appropriate thickness of coating layer on TiO2 can suppress the recombination of photogenerated electrons with the oxidized species, improve the transport rate of electron in TiO2 film and increase the driving force of electron from the excited state of the dye into the conduction band of TiO2, all of which contributed to the improvement of photovolatic performances. However, too thicker overlayer would simultaneously retard the electron injection process, leading to decrease of photocurrent thus the overall conversion efficiency.