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Due to the surface oxide layer or surface defects in the preparation process of nanowires (NWs), resulting in large dark current noise and low detectivity, which seriously limits the detection performance of photodetectors. Here, we successfully synthesized high-quality single-crystalline InP NWs utilizing chemical vapor deposition method and fabricated high-performance top-gated single InP NW photodetectors. The ultra-low noise dark current and high detectivity are obtained, mainly because the passivation layer of HfO2 reduces the defect density on the NW surface and suppresses the background dark current. The low frequency noise current power of the top-gated device is about $2.0\times 10^{ - 28}\,\,\text{A}^{2}$ . Under near-infrared 830 nm laser illumination with 0.05 mW cm $^{ - 2}$ , the top-gated single InP NW photodetector exhibits high responsivity of $1.0\times 10^{5}$ A $\text{W}^{ - 1}$ , external quantum efficiency of $1.4\times 10^{7}$ %, and detectivity of $1.1\times 10^{16}$ Jones, the rise time and fall time are about 7.2 ms and 13.6 ms, respectively. The results demonstrate that the top-gated HfO2-capped InP NWs FET have a broad application in high-performance and low-power photodetectors.

Tin sulfide semiconductor nanowires (NWs) have been widely investigated for photodetection applications because of their good optical and electrical properties. Herein, we synthesized n-type SnS2NWs and then fabricated SnS2NW photodetectors with a ferroelectric polymer side-gate. The strong electric field induced by ferroelectric polymer can effectively suppress the dark current and improve the detectivity in SnS2NW photodetectors. The photodetectors after polarization depletion exhibit a high photoconductive gain of 4.0 × 105and a high responsivity of 2.1 × 105A W−1. Compared with devices without polarization depletion, the detectivity of polarization-depleted photodetectors is improved by at least two orders of magnitude, and the highest detectivity is 1.3 × 1016Jones. Further, the rise and fall time are 56 and 91 ms respectively, which are about tens of times faster than those without polarization depletion. The device also shows a good spectral response from ultraviolet to near-infrared. This study demonstrates that ferroelectric materials can enhance optoelectronic properties of low-dimensional semiconductors for high-performance photodetectors.

Single-photon detectors that can resolve photon number play a key role in advanced quantum information technologies. Despite significant progress in improving conventional photon-counting detectors and developing novel device concepts, single-photon detectors that are capable of distinguishing incident photon number at room temperature are still very limited. We demonstrate a room-temperature photon-number-resolving detector by integrating a field-effect transistor configuration with core/shell-like nanowires. The shell serves as a photosensitive gate, shielding negative back-gated voltage, and leads to a persistent photocurrent. At room temperature, our detector is demonstrated to identify 1, 2, and 3 photon-number states with a confidence of >82%. The detection efficiency is determined to be 23%, and the dark count rate is 1.87 × 10–3Hz. Importantly, benefiting from the anisotropic nature of 1D nanowires, the detector shows an intrinsic photon-polarization selection, which distinguishes itself from existing intensity single-photon detectors. The unique performance for the single-photon detectors based on single nanowire demonstrates the great potential for future single-photon detection applications.

Because of the distinct electronic properties and strong interaction with light, quasi-one-dimensional nanowires (NWs) with semiconducting property have been demonstrated with tremendous potential for various technological applications, especially electronics and optoelectronics. However, until now, most of the state-of-the-art NW photodetectors are predominantly based on the n-type NW channel. Here, we successfully synthesized p-type SnSe and SnS NWs viathe chemical vapor deposition method and fabricated high-performance single SnSe and SnS NW photodetectors. Importantly, these two NW devices exhibit an impressive photodetection performance with a high photoconductive gain of 1.5 × 104(2.8 × 104), good responsivity of 1.0 × 104A W–1(1.6 × 104A W–1), and excellent detectivity of 3.3 × 1012Jones (2.4 × 1012Jones) under near-infrared illumination at a bias of 3 V for the SnSe NW (SnS NW) channel. The rise and fall times can be as efficient as 460 and 520 μs (1.2 and 15.1 ms), respectively, for the SnSe NW (SnS NW) device. Moreover, the spatially resolved photocurrent mapping of the devices further reveals the bias-dependent photocurrent generation. All these results evidently demonstrate that the p-type SnSe and SnS NWs have great potential to be applied in next-generation high-performance optoelectronic devices.