Towards high-performance near-infrared photodetectors based on SnS nanowires

Abstract

Compared with bulk structures, semiconductor nanowires exhibit a higher surface-to-volume ratio, as well as unique electrical and optical properties. Due to its narrow band gap, tin (ii) sulfide (SnS) nano wire is a promising candidate for constructing near-infrared (NIR) photodetectors. Uniformly distributed and well-aligned SnS nanowires were grown on a mica substrate by chemical vapor deposition, and NIR photodetectors with Au (Au-device) and Al (Al-device) as the electrode were fabricated and characterized. Compared to the Au-device, the Al-device achieved higher photodetectivity due to reduced dark current. More importantly by incorporating a photosensitive lead phthalocyanine (PbPc) film into the Al-device, both responsivity and detectivity could be apparently improved, especially at weak light intensities. Under a weak light intensity of 0.79 mW/cm 2the photoresponsivity and specific detectivity were improved from and Jones to 0.96 A/W and Jones, respectively.