High-performance self-powered UV photodetectors based on TiO2 nano-branched arrays.
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.
School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, People's Republic of China.
Yanru
Y
Xie
Lin
L
Wei
Qinghao
Q
Li
Yanxue
Y
Chen
Shishen
S
Yan
Jun
J
Jiao
Guolei
G
Liu
Liangmo
L
Mei