High-gain visible-blind UV photodetectors based on chlorine-doped n-type ZnS nanoribbons with tunable optoelectronic properties

Abstract

Efficient n-type doping of ZnS nanoribbons (NRs) were accomplished by using chlorine (Cl) as the dopant viathermal evaporation. An indium tin oxide (ITO) transparent electrode was used to achieve ohmic contact to the ZnS:Cl NRs. The conductivity of the Cl-doped ZnS NRs was significantly improved as compared with the undoped ones and could be tuned to a wide range of 3–4 orders of magnitude by adjusting the Cl doping level. High-performance nano-photodetectors were constructed based on the ZnS:Cl NRs, which show high sensitivity to the UV light while are nearly blind to the visible light. Notably, the ZnS:Cl NR photodetectors have a photoconductive gain as high as ∼107, which is amongst the highest values obtained for UV nano-photodetectors so far. Our results demonstrate that the n-type ZnS NRs with tunable optoelectronic properties are promising building blocks for nano-optoelectronic devices.