No abstract

One-dimensional semiconductor nanowires (NWs) have been widely applied in photodetector due to their excellent optoelectronic characteristics. However, intrinsic carrier concentration at certain level results in appreciable dark current, which limits the detectivity of the devices. Here, we fabricated a novel type of ferroelectric-enhanced side-gated NW photodetectors. The intrinsic carriers in the NW channel can be fully depleted by the ultrahigh electrostatic field from polarization of P(VDF-TrFE) ferroelectric polymer. In this scenario, the dark current is significantly reduced and thus the sensitivity of the photodetector is increased even when the gate voltage is removed. Particularly, a single InP NW photodetector exhibits high-photoconductive gain of 4.2 × 10(5), responsivity of 2.8 × 10(5) A W(-1), and specific detectivity (D*) of 9.1 × 10(15) Jones at λ = 830 nm. To further demonstrate the universality of the configuration we also demonstrate ferroelectric polymer side-gated single CdS NW photodetectors with ultrahigh photoconductive gain of 1.2 × 10(7), responsivity of 5.2 × 10(6) A W(-1) and D* up to 1.7 × 10(18) Jones at λ = 520 nm. Overall, our work demonstrates a new approach to fabricate a controllable, full-depleted, and high-performance NW photodetector. This can inspire novel device structure design of high-performance optoelectronic devices based on semiconductor NWs.

An advanced visible/infrared dual-band photodetector with high-resolution imaging at room temperature is proposed and demonstrated for intelligent identification based on the 2D GaSe/GaSb vertical heterostructure. It resolves the challenges of producing large-scale 2D growth, achieving fast response speed, outstanding detectivity, and lower manufacture cost, which are the main obstacles for industrialization of 2D-materials-based photodetection.

Two-dimensional materials are promising candidates for electronic and optoelectronic applications. MoTe2 has an appropriate bandgap for both visible and infrared light photodetection. Here we fabricate a high-performance photodetector based on few-layer MoTe2. Raman spectral properties have been studied for different thicknesses of MoTe2. The photodetector based on few-layer MoTe2 exhibits broad spectral range photodetection (0.6-1.55 μm) and a stable and fast photoresponse. The detectivity is calculated to be 3.1 × 10(9) cm Hz(1/2) W(-1) for 637 nm light and 1.3 × 10(9) cm Hz(1/2) W(-1) for 1060 nm light at a backgate voltage of 10 V. The mechanisms of photocurrent generation have been analyzed in detail, and it is considered that a photogating effect plays an important role in photodetection. The appreciable performance and detection over a broad spectral range make it a promising material for high-performance photodetectors.