Konstantatos, Gerasimos, Badioli, Michela, Gaudreau, Louis, Osmond, Johann, Bernechea, Maria ![]() |
Abstract
Graphene is an attractive material for optoelectronics1 and photodetection applications2, 3, 4, 5, 6 because it offers a broad spectral bandwidth and fast response times. However, weak light absorption and the absence of a gain mechanism that can generate multiple charge carriers from one incident photon have limited the responsivity of graphene-based photodetectors to ~10−2 A W−1. Here, we demonstrate a gain of ~108 electrons per photon and a responsivity of ~107 A W−1 in a hybrid photodetector that consists of monolayer or bilayer graphene covered with a thin film of colloidal quantum dots. Strong and tunable light absorption in the quantum-dot layer creates electric charges that are transferred to the graphene, where they recirculate many times due to the high charge mobility of graphene and long trapped-charge lifetimes in the quantum-dot layer. The device, with a specific detectivity of 7 × 1013 Jones, benefits from gate-tunable sensitivity and speed, spectral selectivity from the short-wavelength infrared to the visible, and compatibility with current circuit technologies.
Item Type: | Article |
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Date Type: | Published Online |
Status: | Published |
Schools: | Engineering |
Subjects: | T Technology > TA Engineering (General). Civil engineering (General) |
Publisher: | Nature Publishing Group |
ISSN: | 1748-3387 |
Date of First Compliant Deposit: | 11 August 2016 |
Date of Acceptance: | 23 March 2012 |
Last Modified: | 01 Nov 2022 11:04 |
URI: | https://orca.cardiff.ac.uk/id/eprint/93768 |
Citation Data
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