Controllable synthesis of p-type Cu2S nanowires for self-driven NIR photodetector application

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology 2017-02, Vol.19 (2), Article 35
• Main Authors: Wu, Chun-Yan, Pan, Zhi-Qiang, Liu, Zhu, Wang, You-Yi, Liang, Feng-Xia, Yu, Yong-Qiang, Wang, Li, Luo, Lin-Bao
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Inorganic Chemistry; Lasers; Materials Science; Nanotechnology; Optical Devices; Optics; Photonics; Physical Chemistry; Research Paper
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-016-3736-z

Face-centered cubic Cu 2 S nanowires with length of up to 50 μm and diameters in the range of 100–500 nm are synthesized on Si substrates through the chemical vapor deposition method using a mixed gas of Ar and H 2 as the carrier gas under a chamber pressure of about 700 Torr. It was found that the growth of quasi 1D nanostructure followed a typical vapor-liquid-solid (VLS) mechanism in which the element Cu was reduced by H 2 as the catalyst. The as-synthesized Cu 2 S nanowires exhibited typical p-type semiconducting characteristics with a conductivity of about 600 S cm −1 and a hole mobility ( μ h ) of about 72 cm 2  V −1  s −1 . Further study reveals that p-Cu 2 S nanowires/n-Si heterojunction exhibits distinct rectifying characteristics with a turn-on voltage of ~0.6 V and a rectification ratio of ~300 at ±1 V in the dark and a pronounced photovoltaic behavior with an open circuit voltage ( V oc ) of 0.09 V and a short circuit current ( I sc ) of 65 nA when illuminated by the NIR light (790 nm, 0.35 mW cm −1 ), giving rise to a responsivity ( R ) about 0.8 mA W −1 and specific detectivity ( D *) 6.7 × 10 10  cm Hz 1/2  W −1 at zero bias, which suggests the potential of as-synthesized Cu 2 S nanowires applied in the field of self-driven NIR photodetector.