School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, People's Republic of China.
Nanotechnology. 2014 Feb 21;25(7):075202. doi: 10.1088/0957-4484/25/7/075202. Epub 2014 Jan 22.
Nano-branched TiO2 arrays were fabricated on fluorine-doped tin oxide (FTO) glass by a facile two-step chemical synthesis process. Self-powered UV photodetectors based on photoelectrochemical cells (PECs) were assembled using these TiO2 nano-branched arrays as photoanodes. These visible-blind self-powered UV photodetectors exhibit high sensitivity and high-speed photoresponse. Compared with photodetectors based on bare TiO2 nanorod arrays, TiO2 nano-branched arrays show drastically improved photodetecting performance as photoanodes. The photosensitivity increases from 0.03 to 0.22 A W(-1) when optimized nano-branched TiO2 arrays are used, corresponding to an incident photon-to-current conversion efficiency higher than 77%. The UV photodetectors also exhibit excellent spectral selectivity and fast response (0.05 s decay time). The improved performance is attributed to a markedly enlarged TiO2/electrolyte contact area and good electron conductivity in the one-dimensional, well-aligned TiO2 nanorod trunk.
纳米枝状 TiO2 阵列通过简便的两步化学合成工艺在掺氟氧化锡（FTO）玻璃上制备。使用这些 TiO2 纳米枝状阵列作为光电阳极，组装基于光电化学电池（PEC）的自供电紫外光探测器。这些可见盲自供电紫外光探测器表现出高灵敏度和高速光响应。与基于裸 TiO2 纳米棒阵列的光探测器相比，TiO2 纳米枝状阵列作为光阳极显示出明显改善的光电探测性能。当优化的纳米枝状 TiO2 阵列被使用时，灵敏度从 0.03 增加到 0.22 A W(-1)，对应于高于 77%的入射光子到电流的转换效率。紫外光探测器还表现出优异的光谱选择性和快速响应（0.05 s 衰减时间）。性能的提高归因于一维、良好排列的 TiO2 纳米棒主干中 TiO2/电解质接触面积的显著增大和良好的电子导电性。
