TY - JOUR
T1 - High quality ZnO-TiO 2 core-shell nanowires for efficient ultraviolet sensing
AU - Shao, Dali
AU - Sun, Hongtao
AU - Xin, Guoqing
AU - Lian, Jie
AU - Sawyer, Shayla
N1 - Funding Information:
The authors gratefully acknowledge support from National Security Technologies through NSF Industry/University Cooperative Research Center Connection One . The authors also acknowledge the National Science Foundation Smart Lighting Engineering Research Center ( EEC-0812056 ) and a NSF career award DMR 1151028.
PY - 2014/9/30
Y1 - 2014/9/30
N2 - High quality ZnO-TiO 2 core-shell nanowires (NWs) have been fabricated via a facile two-step method: growth of ZnO nanowires by hydrothermal synthesis and then coating of highly uniform TiO 2 shell using atomic layer deposition (ALD) technique. The ultraviolet (UV) emission intensity of the ZnO-TiO 2 core-shell NWs is largely quenched due to an efficient electron-hole separation that reduces the band-to-band recombinations. To the contrary, the absorption of the ZnO-TiO 2 core-shell NWs in both UV and visible region is enhanced, which is attributed to the antireflection properties of the TiO 2 shell. An UV photodetector fabricated from the ZnO-TiO 2 core-shell NWs showed a maximum photoresponsivity as high as 495 A/W at 373 nm under -10 V, which is ∼8 times higher than that of the photodetector fabricated from bare ZnO NWs. In addition, the transient response of the ZnO-TiO 2 core-shell NWs is improved by 6 times as compared to that of the bare ZnO NWs. The results presented in this work suggest that ZnO-TiO 2 core-shell NWs may be promising for various optoelectronics applications including: UV photodetectors, optical switches, optical fibers and solar cells.
AB - High quality ZnO-TiO 2 core-shell nanowires (NWs) have been fabricated via a facile two-step method: growth of ZnO nanowires by hydrothermal synthesis and then coating of highly uniform TiO 2 shell using atomic layer deposition (ALD) technique. The ultraviolet (UV) emission intensity of the ZnO-TiO 2 core-shell NWs is largely quenched due to an efficient electron-hole separation that reduces the band-to-band recombinations. To the contrary, the absorption of the ZnO-TiO 2 core-shell NWs in both UV and visible region is enhanced, which is attributed to the antireflection properties of the TiO 2 shell. An UV photodetector fabricated from the ZnO-TiO 2 core-shell NWs showed a maximum photoresponsivity as high as 495 A/W at 373 nm under -10 V, which is ∼8 times higher than that of the photodetector fabricated from bare ZnO NWs. In addition, the transient response of the ZnO-TiO 2 core-shell NWs is improved by 6 times as compared to that of the bare ZnO NWs. The results presented in this work suggest that ZnO-TiO 2 core-shell NWs may be promising for various optoelectronics applications including: UV photodetectors, optical switches, optical fibers and solar cells.
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U2 - 10.1016/j.apsusc.2014.06.182
DO - 10.1016/j.apsusc.2014.06.182
M3 - Article
AN - SCOPUS:84906785056
SN - 0169-4332
VL - 314
SP - 872
EP - 876
JO - Applied Surface Science
JF - Applied Surface Science
ER -