【作者】 张坤峰；

【导师】 李道荣；

【作者基本信息】 河南工业大学 ， 应用化学， 2010， 硕士

【摘要】 20世纪90年代发展起来的染料敏化太阳能电池具有廉价、高效、制作工艺简单、寿命长的优点,对它的研究和应用将有利于解决当今能源危机和环境污染的问题,具有非常重要的现实和长远意义。为提高DSSC电池的光阳极的光电转换性能,本文分别采用磁场辅助金属离子掺杂,非金属元素共掺杂与金属氧化物包覆等方面对TiO₂材料进行改性,并组装成DSSC电池,研究其光电转换性能。借助UV-Vis、FTIR、PL、SEM/EDS、XRD、TEM、SEM及XPS等手段对材料进行了表征。结果表明,外加强磁场使材料的粒径减小,颗粒分布均匀,利于金属离子掺杂进入TiO₂内,降低了TiO₂的带隙能,又降低了电子空穴对复合率,提高了催化剂的电子空穴对分离效率,增大了TiO₂的光电转换效率。以TiNi_xO_2+x与TiCo_xO_2+x材料组装的DSSC的最大光电转换效率分别达到5.06%与4.70%;N、C元素的引入降低了TiO₂的带隙能,拓展了TiO₂在可见光区的光吸收,有效地提高了TiO₂的光电转换效率。XRD与XPS显示C,N掺杂进入TiO₂晶格取代O原子。TiO_xN_yC_z在400℃下煅烧5h时显示出最佳的光电转换性能,DSSC的光电转换效率达8.39%;ZnO包覆TiO₂利用半导体材料间的耦合作用形成掺杂能级,使得较低能量的光子能激发TiO₂掺杂能级上捕获的电子和空穴,从而提高了TiO₂光子的利用率。二者之间形成的势垒可以阻止TiO₂因激发而产生的光生电子向电解质中传递,能有效地抑制光生电子-空穴对的复合,显著地提高了TiO2的光电转化效率,DSSC最大光电转换效率达到4.67%。更多还原

【Abstract】 Dye sensitization solar cells have emerged since the 1990s as highly effective, simple rocess, long-lasting, and cheap photovoltaic technology. Its research and application will be beneficial to the solution of the energy crisis and environmental pollution. In order to enhance photoelectric conversion to photo-electrode of DSSC, the article uses metallic ion doping under the magnetic field, non-metallic element doping and Metal oxide coating separately to modifing TiO₂. Photovoltaic performances have been studied by assembling the DSSC. The material has been carried on UV-Vis, FTIR, PL, SEM/EDS, XRD, TEM, SEM and XPS.The results revealed that the external magnetic field not only decreased crystalline size of modified TiO₂ and distributed particles uniformity, but also cut down the electron-hole pairs recombination rate, and enhanced the conversion efficiency of the material. The conversion efficiency of DSSC assembled by TiNi_xO_2+x and TiCo_xO_2+x materials were 5.06% and 4.70%, respectively.The co-doped TiO₂ nanoparticles showed high photoactivity under visible light irradiation, which may be ascribed to absorption edge shift to longer wavelength and lower recombination rate of TiO₂. XRD and XPS results also showed that the doped C and N atoms incorporated into the lattice of TiO2 substitute for O atoms. It was found that C, N-co-doped TiO₂ （400 oC） exhibited the highest photocatalytic activity because of the good synergistic effect of co-doped carbon and nitrogen atoms. The conversion efficiency of DSSC got up to 8.39%The doped energy-bands were formed from ZnO coated TiO₂ by the coupling effect of semiconductor material. So electrons and holes captured from doped energy-bands of TiO₂ could be excitated by low-energy photons. Utilization ratio of photons increased, too. The potential barrier could stop electrons excitated from TiO2 transferring into electrolyte. The recombination of lectrons and holes were inhibitted, too. Especially, the photocatalytic activity of TiO₂ significantly was improved, and the conversion efficiency of DSSC got up to 4.67%更多还原