Responsivity

About: Responsivity is a research topic. Over the lifetime, 9918 publications have been published within this topic receiving 186118 citations.

A Highly Responsive Organic Image Sensor Based on a Two‐Terminal Organic Photodetector with Photomultiplication

Abstract: Highly responsive organic image sensors are crucial for medical imaging applications. To enhance the pixelwise photoresponse in an organic image sensor, the integration of an organic photodetector with amplifiers, or the use of a highly responsive organic photodetector without an additional amplifying component, is required. The use of vertically stacked, two-terminal organic photodetectors with photomultiplication is a promising approach for highly responsive organic image sensors owing to their simple two-terminal structure and intrinsically large responsivity. However, there are no demonstrations of an imaging sensor array using organic photomultiplication photodetectors. The main obstacle to a sensor array is the weak-light sensitivity, which is limited by a relatively large dark current. Herein, a highly responsive organic image sensor based on monolithic, vertically stacked two-terminal pixels is presented. This is achieved using pixels of a vertically stacked diode-type organic photodetector with photomultiplication. Furthermore, applying an optimized injection electrode and additionally stacked rectifying layers, this two-terminal device simultaneously demonstrates a high responsivity (>40 A W-1 ), low dark current, and high rectification under illumination. An organic image sensor based on this device with an extremely simple architecture exhibits a high pixel photoresponse, demonstrating a weak-light imaging capability even at 1 µW cm-2 .

High performance, self-powered photodetectors based on a graphene/silicon Schottky junction diode

Abstract: Electron–hole pair separation and photocurrent conversion at two-dimensional (2D) and three-dimensional (3D) hybrid interfaces are important for achieving high performance, self-powered optoelectronic devices such as photodetectors. In this regard, herein, we designed and demonstrated a graphene/silicon (Gr/Si) (2D/3D) van der Waals (vdW) heterostructure for high-performance photodetectors, where graphene acts as an efficient carrier collector and Si as a photon absorption layer. The Gr/Si heterojunction exhibits superior Schottky diode characteristics with a barrier height of 0.76 eV and shows good performance as a self-powered detector, responding to 532 nm at zero bias. The self-powered photodetector functions under the mechanism of photovoltaic effect and exhibits responsivity as high as 510 mA W−1 with a photo switching ratio of 105 and a response time of 130 μs. The high-performance vdW heterostructure photodetector demonstrated herein is attributed to the Schottky barrier that effectively prolongs the lifetime of photo-excited carriers, resulting in fast separation and transport of photoexcited carriers. The self-powered photodetector with superior light harvesting and carrier transport behaviour is expected to open a window for the technological implementation of Si-based monolithic optoelectronic devices.

High‐Performance Ferroelectric Polymer Side‐Gated CdS Nanowire Ultraviolet Photodetectors

Abstract: An efficient ferroelectric-enhanced side-gated single CdS nanowire (NW) ultraviolet (UV) photodetector at room temperature is demonstrated. With the ultrahigh electrostatic field from polarization of ferroelectric polymer, the depletion of the intrinsic carriers in the CdS NW channel is achieved, which significantly reduces the dark current and increases the sensitivity of the UV photodetector even after the gate voltage is removed. Meanwhile, the low frequency noise current power of the device reaches as low as 4.6 × 10−28 A2 at a source-drain voltage Vds = 1 V. The single CdS NW UV photodetector exhibits high photoconductive gain of 8.6 × 105, responsivity of 2.6 × 105 A W−1, and specific detectivity (D*) of 2.3 × 1016 Jones at a low power density of 0.01 mW cm−2 for λ = 375 nm. In addition, the spatially resolved scanning photocurrent mapping across the device shows strong photocurrent signals near the metal contacts. This is promising for the design of a controllable, high-performance, and low power consumption ultraviolet photodetector.

Inas quantum dot infrared photodetectors with In0.15Ga0.85As strain-relief cap layers

Abstract: We report InAs quantum dot infrared photodetectors that utilize In0.15Ga0.85As strain-relief cap layers. These devices exhibited normal-incidence photoresponse peaks at 8.3 or 8.8 μm for negative or positive bias, respectively. At 77 K and −0.2 V bias the responsivity was 22 mA/W and the peak detectivity D* was 3.2×109 cm Hz1/2/W.