Interfacial state induced ultrasensitive ultraviolet light photodetector with resolved flux down to 85 photons per second
II–VI group, detectivity, Schottky barrier diode, optoelectronic device, interfacial states
We present an ultrasensitive ultraviolet (UV) detector based on a p-type ZnS nanoribbon (NR)/indium tin oxide (ITO) Schottky barrier diode (SBD). The device exhibits a pseudo-photovoltaic behavior which can allow the SBD to detect UV light irradiation with incident power of 6 × 10–17 W (~85 photons/s on the NR) at room temperature, with excellent reproducibility and stability. The corresponding detectivity and photoconductive gain are calculated to be 3.1 × 1020 cm·Hz1/2·W–1 and 6.6 × 105, respectively. It is found that the presence of the trapping states at the p-ZnS NR/ITO interface plays a crucial role in determining the ultrahigh sensitivity of this nanoSBDs. Based on our theoretical calculation, even ultra-low photon fluxes on the order of several tens of photons could induce a significant change in interface potential and consequently cause a large photocurrent variation. The present study provides new opportunities for developing high-performance optoelectronic devices in the future.
Tsinghua University Press
Yong-Qiang Yu,Lin-Bao Luo,Ming-Zheng Wang,Bo Wang,Long-Hui Zeng,Chun-Yan Wu,Jian-Sheng Jie,Jian-Wei Liu,Li Wang,Shu-Hong Yu, Interfacial state induced ultrasensitive ultraviolet light photodetector with resolved flux down to 85 photons per second. NanoRes.2015, 8(4): 1098–1107