Ultrasensitive and ultrathin phototransistors and photonic synapses using perovskite quantum dots grown from graphene lattice

Abstract

Organic-inorganic halide perovskite quantum dots (PQDs) constitute an attractive class of materials for many optoelectronic applications. However, their charge transport properties are inferior to materials like graphene. On the other hand, the charge generation efficiency of graphene is too low to be used in many optoelectronic applications. Here, we demonstrate the development of ultrathin phototransistors and photonic synapses using a graphene-PQD (G-PQD) superstructure prepared by growing PQDs directly from a graphene lattice. We show that the G-PQDs superstructure synchronizes efficient charge generation and transport on a single platform. G-PQD phototransistors exhibit excellent responsivity of 1.4 × 108 AW–1 and specific detectivity of 4.72 × 1015 Jones at 430 nm. Moreover, the light-assisted memory effect of these superstructures enables photonic synaptic behavior, where neuromorphic computing is demonstrated by facial recognition with the assistance of machine learning. We anticipate that the G-PQD superstructures will bolster new directions in the development of highly efficient optoelectronic devices.

Artificial visual systems enabled by quasi–two-dimensional electron gases in oxide superlattice nanowires

“…On the other hand, sequential negative electric pulses (amplitude, −5 V; duration, 10 ms; interval, 1 s) are applied onto the gate terminal to mimic the electronic suppression function. Similar strategies that involve light-induced potentiation and electronic-induced suppression have been reported by several recent works (33)(34)(35). While under a negative gate voltage, more electrons are concentrated at the NW surface and captured by oxygen molecules (O 2 ) adsorbed onto the NW surface: O 2 (g) + e − → O 2 − (ad).…”

Two-Dimensional Near-Atom-Thickness Materials for Emerging Neuromorphic Devices and Applications

“…The device showed a photoresponsivity of 1.4 × 108 A W −1 at 430 nm and a specific detectivity (D∗) of 4.72 × 10 15 Jones. It also showed STP, LTP, LTD, data retention of 3 × 10 3 s ( Figure 7 F), PPF ( Figure 7 G), and other essential synaptic characteristics with a low energy consumption of 36.75 pJ per spike ( Pradhan et al., 2020 ). Ni et al.…”

“… (G) PPF index for varying intervals between two consecutive pulses at different wavelengths. Reprinted with permission from ( Pradhan et al., 2020 ). © The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science.…”

“…Their desirable properties, including atomic thickness, dangling-bond-free surfaces, mechanical strength, high integration density, tunable electrical transport, and optical properties, as well as low energy consumption, make them ideal candidates for applications in a wide range of electronic devices ( Gupta et al., 2015 ; Mas-Ballesté et al., 2011 ; Xia et al., 2017 ). More recently, the applications of 2D materials have been extensively studied for energy-efficient and high-performing artificial synapses ( Arnold et al., 2017 ; Chen et al., 2019c ; Dev et al., 2020 ; Hu et al., 2019 ; Jiang et al., 2017 ; Kalita et al., 2019 ; Kim et al., 2019c ; Krishnaprasad et al., 2019 ; Kumar et al., 2019 ; Li et al., 2018 ; Liu et al., 2019 ; Mao et al., 2019 ; Paul et al., 2019 ; Pradhan et al., 2020 ; Xie et al., 2018a , 2018b ; Xu et al., 2019 ; Yan et al., 2019a ; Yi et al., 2018 ; Zhu et al., 2019 ). Furthermore, owing to their dangling-bonds-free surface and atomically thin nature, a variety of 2D materials-based heterostructures have been developed in spite of their lattice mismatch ( Novoselov et al., 2016 ).…”

Organic neuromorphic devices: Past, present, and future challenges

“…By exploiting the excellent optoelectronic properties of HPs, new memristors that can be programmed via both electrical and optical programming spikes have been recently realized. 86,87 This paves the way for new optoelectronic neuromorphic architectures that combine multiple modalities for accessing memory states.…”