Transient and Flexible Photodetectors

Abstract

With the rapid development of technology, electronic devices have become omnipresent in our daily life as they have brought much convenience in every aspect of human activity. Side-by-side, electronic waste (e-waste) has become a global environmental burden creating an ever-growing ecological problem. The transient device technology in which the devices can physically disappear completely in different environmental conditions has attracted widespread attention in recent years owing to its emerging application potential spanning from biomedical to military use. In this work, we demonstrated the first attempt for a dissolvable ecofriendly flexible photodetector using a hybrid of graphene and chlorophyll on a poly­(vinyl alcohol) substrate. The whole device can physically disappear in aqueous solutions in a time span of ∼30 min, while it shows a photoresponsivity of ∼200 A W–1 under ambient conditions. The high carrier mobility of graphene and strong absorption strength of a green photon harvesting layer, chlorophyll, result in the photocurrent gain of the device as high as 103 with subsecond response time under the illumination of red light. The newly designed photodetector shown here yields zero waste with a minimum impact on the environment, which is very useful for the development of the sustainability of our planet.

Rippled Metallic‐Nanowire/Graphene/Semiconductor Nanostack for a Gate‐Tunable Ultrahigh‐Performance Stretchable Phototransistor

“…The free carrier density ( N ) in such a composite system can be represented by Equation () [ 45,62 ] where η is the exciton generation quantum efficiency, is the energy of incident photons, and τ( P ) is the carrier lifetime and a function of power, P . τ( P ) in this hybrid nanostack can be expressed as Equation () [ 45,62 ] where τ 0 is the carrier lifetime under an excitation power P 0 in which all the surface states are occupied, n is the fitting parameter. At low excitation intensity, the photoinduced holes are trapped at the oxygen vacancies containing one electron predominantly present at the ZnO‐NP surface states, which provides sufficient time for the electrons to transfer to the underlying graphene channel.…”

Enhanced laser action from smart fabrics made with rollable hyperbolic metamaterials

“…To be integrated onto human body, these devices must be biocompatible and be able to withstand mechanical deformation and different bending curvatures 3,4 . This promising market of wearable photonics and optoelectronics has inspired a number of demonstrations such as flexible photodetectors 5 , stretchable laser systems 6 , artificial electronic skins 3 , paper-based memory devices 7 , and flexible optoelectronic fibers and textiles [8][9][10][11] . The developed flexible photonic devices possess advanced functionalities beyond their rigid counterparts.…”

Chlorophylls as Molecular Semiconductors: Introduction and State of Art

“…The device featured ON/OFF ratio of 3.5 × 10 3 , and threshold voltage of −7.1 V. As expected, the carrier mobility is substantially smaller than the perfectly aligned ZnChl-1 aggregates, [37] but is comparable with other hole transporters such as poly(3-hexylthiophene) (P3HT). The LUMO of [58] Copyright 2018, American Chemical Society.…”