基于铝离子掺杂二氧化钛薄膜的染料敏化太阳能电池的光电性能

采用水热法制备出Al3+掺杂二氧化钛薄膜,通过玻璃棒涂于导电玻璃上,在450°C的温度下烧结并将其用N3染料敏化制成染料敏化太阳能电池(DSSCs).通过X射线光电子能谱(XPS)、X射线衍射(XRD)、扫描电镜(SEM)及DSSCs测试系统对其进行了测试表征,研究了Al3+掺杂对TiO2晶型及染料敏化太阳能电池的光电性能影响.XPS数据显示Al3+成功掺杂到了TiO2晶格内,由于Al3+的存在,对半导体内电子和空穴的捕获及阻止电子/空穴对的复合发挥重要作用.莫特-肖特基曲线显示掺杂Al3+后二氧化钛平带电位发生正移,并导致电子从染料注入到TiO2的驱动力提高.DSSCs系统测试结果表明,Al3+掺杂的TiO2薄膜光电效率达到6.48%,相对于无掺杂的纯二氧化钛薄膜光电效率(5.58%),其光电效率提高了16.1%,短路光电流密度从16.5mA·cm-2提高到18.2mA·cm-2.

Photovoltaic Performance of Dye-Sensitized Solar Cells Based on Al-Doped TiO2 Thin Films

Al-doped TiO 2 thin films were synthesized by the hydrothermal method.To prepare a working electrode,a TiO 2 or AlTiO 2 slurry was coated onto a fluorine-doped tin oxide glass substrate by the doctor blade method and the coated substrate was sintered at 450°C.TiO 2 and Al-doped TiO 2 films were characterized by X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),scanning electron microscopy(SEM),and tested by the dye-sensitized solar cell(DSSCs)system.The influences of Al-doping on TiO 2 crystal form and the photovoltaic performance of DSSCs were investigated.X-ray photoelectron spectroscopy(XPS)data indicate that the doped Al ions exist in the form of Al 3+ ,and these ions play a role as e - or h + traps and reduce the e - /h + pair recombination rate.The corresponding Mott-Schottky plot indicates that the Al-doped TiO 2 photoanode shifts the flat band potential positively.The positive shift of the flat band potential improves the driving force of injected electrons from the LUMO of the dye to the conduction band of TiO 2 .The Al-doped TiO 2 thin film shows a photovoltaic efficiency of 6.48%, which is higher than that of the undoped TiO 2 thin film(5.58%)and the short-circuit photocurrent density increases from 16.5 to 18.2 mA·cm -2 .