有机电解液中TiO2纳米管阵列的制备及其光电性能

在氟化铵/丙三醇电解液中,采用恒压直流阳极氧化法制备TiO2纳米管阵列,并研究其在空气热处理过程中的结晶行为,最后将管阵列作为光阳极组装成染料敏化太阳能电池(DSSC),研究氧化时间和热处理温度对其光电性能的影响。结果表明:TiO2纳米管阵列的形成是一个随时间渐进演变的过程;随着氧化时间的延长,纳米管长度逐渐增大,当时间为70 h时,长度达到5μm左右;管阵列在空气中于400℃以下热处理后,由锐钛矿相构成,450和500℃热处理时,由锐钛矿相和金红石相构成,同时管阵列结构具有良好的高温稳定性。光电性能测试显示,20 V、70 h制备的TiO2纳米管阵列经450℃热处理后,组装成的染料敏化太阳能电池的(有效面积1 cm2)光电转换效率可达到0.989%。

Fabrication of TiO2 nanotube arrays in organic electrolyte and its photoelectric performances

TiO2 nanotube arrays were fabricated by anodic oxidation in the mixture of NH4F/glycerol at a constant potential.The crystalline behavior of TiO2 nanotube arrays during heat treatment in air atmosphere was studied.Then,the dye-sensitized solar cells(DSSC) were assembled with the prepared TiO2 nanotube arrays electrodes.The effects of anodization time and heat treatment temperature on the photoelectric performances of DSSC were investigated.The results show that the formation process of TiO2 nanotube arrays is a gradual evolving process.The length of the nanotube increases obviously with increasing the anodization time.When the anodization time is 70 h,the length is about 5 μm.Only the anatase phase is found in the TiO2 nanotube arrays heat-treated at 400 ℃ or lower temperatures,while both the anatase and rutile phases are found in the tubes annealed at 450 ℃ and 500 ℃.Furthermore,the structure of TiO2 nanotube arrays has high temperature stability.Compared with other DSSC samples,the DSSC assembled with the TiO2 nanotube arrays(20 V,70 h) annealed at 450 ℃ shows the best photoelectric performance that the light-to-electrical energy conversion efficiency is 0.989%.