High-Response, Ultrafast-Speed, and Self-Powered Photodetection Achieved in InP@ZnS-MoS₂ Phototransistors with Interdigitated Pt Electrodes

Abstract

Various hybrid zero-dimensional/two-dimensional (0D/2D) systems have been developed to fabricate phototransistors with better performance compared to two-dimensional (2D) layered materials as well as broaden potential applications. Herein, we integrated environment-friendly InP@ZnS core–shell QDs with high efficiency of light absorption and light-emitting properties with bilayer MoS2 for the realization of 0D/2D mixed-dimensional phototransistors. Interdigitated (IDT) electrodes with Pt-patterned arrays, acting as light collectors as well as plasmonic resonators, can further enhance light harvesting from the InP@ZnS-MoS2 hybrid phototransistors, contributing to achieving a photoresponsivity as high as 1374 A·W–1. Moreover, thanks to the asymmetric Pt/MoS2 Schottky junction at the source/drain contact, a self-powered characteristic with an ultrafast speed of 21.5 μs was achieved, which is among the best performances for 2D layered material-based phototransistors. In terms of these features, we demonstrated the artificial synapse network with short-time plasticity based on the self-powered photodetection device. Our work reveals the great potential of 0D/2D hybrid phototransistors for high-response, ultrafast-speed, and self-powered photodetectors coupled with artificial neuromorphic function.

A review of molybdenum disulfide (MoS2) based photodetectors: from ultra-broadband, self-powered to flexible devices

“…431 The MoS 2 /GaAs heterojunction photodetectors operated between 400-950 nm and showed highest photoresponsivity of 400 mA W À1 and detectivity of 4 Â 10 12 Jones at 500 nm at zero bias voltage, which is a self-powered photodetection. Shi et al 432 integrated 0D InP@ZnS core-shell QDs with 2D bilayer MoS 2 to develop selfpowered hybrid phototransistors by using interdigitated Pt electrodes which acted as light collectors as well as plasmonic resonators. 0D/2D InP@ZnS/MoS 2 hybrid photodetectors showed photoresponsivity of 1374 A W À1 and self-powered properties with a fast photospeed of 21.5 ms.…”

Toward Green Optoelectronics: Environmental-Friendly Colloidal Quantum Dots Photodetectors

“…In addition to the core-shell device structure, environmentally friendly core-shell QDs have been developed and employed for PD applications. Shi et al (2020) proposed a hybrid PD comprising InP/ZnS core-shell QDs and bilayer MoS 2 , as shown in Figure 5G. Due to the strong overlap in the absorption spectrum between core-shell QDs and MoS 2 , plasmon-enhanced nonradiative energy transfer occurred in the hybrid 0D/2D system.…”

Self-Powered Sensors: New Opportunities and Challenges from Two-Dimensional Nanomaterials

“…In this context, the concept of self-powered neuromorphic applications targets self-driven artificial neuroprocessing with respect to the architecture as well as the physical energy source. In 2020, Rosei et al presented mixed dimensional (0D/2D) phototransistors with excellent photoresponsivity as high as 1374 A·W −1 under self-powered operation [ 81 ]. Using the proposed phototransistors, they also demonstrated artificial synaptic behaviors, such as excitatory postsynaptic and paired-pulse facilitation, opening up the development of the self-driven neuromorphic system ( Figure 16 a–c).…”

“… Self-powered neuromorphic systems: ( a ) the InP@ZnS-MoS 2 hybrid phototransistor and a neural network with a multiple series−parallel synapses schematic, ( b ) paired-pulse facilitation (PPF) induced by two laser pulses under a 532 nm laser at 170 mW·cm −2 , and ( c ) dependence of the PPF on the interval between paired pulses (Δt) from a 532 nm laser at 170 mW·cm −2 ; the inset shows the variance of the photovoltage as a function of pulse frequency from 2000 to 3200 Hz. Reproduced with permission from [ 81 ], Copyright 2020, American Chemical Society. ( d ) A self-powered system using carbon-NGs cells connected in series with a memristor.…”