Electric‐Dipole Gated Two Terminal Phototransistor for Charge‐Coupled Device

Abstract

The demand for charge‐coupled device (CCD) imagers has surged exponentially during the last decade owing to their exceptionally high quality and low noise imaging. However, they are still confronting the performance constraints of high operation power, low speed, and limited charge integration. Here, the electric‐dipole gated phototransistor operation without external gate bias is reported by using high‐k HfO2 dielectric material. The electrostatic coupling of photogenerated charges from the Si with the graphene channel through a 10 nm HfO2 layer is demonstrated. The device exhibits remarkable performance in the broadband spectrum (266–1342 nm) at low drain bias voltage. The high values of responsivity, external quantum efficiency, and detectivity of 3.7 × 103 A W−1, 0.72 × 104, and 6.20 × 1013 cmHz½ W−1, respectively, for 800 nm wavelength and 3.3 × 103 A W−1, 1.31 × 104, and 5.61 × 1013 cmHz½ W−1, respectively, for 400 nm wavelength without gate are achieved. This discovery may potentially eliminate the requirement for gate terminals from commercial CCD devices. The power efficient features of this gateless image sensor can be fabricated at the industrial scale for the future machine vision market.

Tuning the catalytic performance of CaSnO3 by developing an S-scheme p–n heterojunction through Ag6Si2O7 doping

“…21–24 Its high melting point and wide bandgap have proven CaSnO 3 a valuable material in a range of applications, including ceramic dielectric bodies, sensors, anode materials for lithium-ion batteries, piezo-catalysts, and photocatalysis. 25,26 To date, the integration of CaSnO 3 with other semiconductors to develop a heterostructure has been a successful approach in separating photoinduced e − /h + pairs because of the existence of an internal electric field and closely connected interfaces. Various composite photocatalysts related to CaSnO 3 have also been reported, such as rGO/CaSnO 3 (ref.…”

Fabrication of a self-powered broadband photodetector by 50% replacement of Pb by Mg in the CH3NH3Pb0.5Mg0.5Cl2I perovskite lattice

“…41–43 Each specific application has its own minimum required figures-of-merit values. Applications such as visible image sensing, medical imaging and spectroscopy require photodetectors with response in the UV and visible range with very high responsivity and response time in the range of ns to ms. 44,45 Applications such as fibre communication, heterodyne measurements and mode beat monitoring, require detectors with ultra-fast response time in the range of a few ps.…”

“…[41][42][43] Each specific application has its own minimum required figures-of-merit values. Applications such as visible image sensing, medical imaging and spectroscopy require photodetectors with response in the UV and visible range with very high responsivity and response time in the range of ns to ms. 44,45 Applications such as fibre communication, heterodyne measurements and mode beat monitoring, require detectors with ultra-fast response time in the range of a few ps. Given the scenario, our fabricated photodetector with a responsivity of few mA W À1 and response time of 411 ms, sensitive to the UV-Vis-NIR spectrum, will be useful for applications such as optical smoke detectors, ambient light sensors and optical power meters.…”

Enhanced sub-band gap photosensitivity by an asymmetric source–drain electrode low operating voltage oxide transistor

“…Organic and metal oxide thin film transistors (TFTs) have generated enormous interest for their application in flat panel displays due to their high carrier mobility, low off current and low manufacturing cost with large area fabrication. 1,2 Besides, their distinct optoelectronic properties, such as high photoresponsivity and efficient light emission from the semiconductor channel, enable us to develop optical sensors [3][4][5] and light emitting transistors, 6 respectively. Again, by using asymmetric work function source-drain electrodes of a TFT, it is possible to modulate charge injection/extraction from the source and drain electrodes independently which can add extra functionality to the electrical characteristics of the TFT.…”