Thermoelectrically Driven Photocurrent Generation in Femtosecond Laser Patterned Graphene Junctions

Abstract

Single and few-layer graphene photodetectors have attracted much attention in the past few years. Pristine graphene shows a very weak response to visible light; hence, fabrication of complex graphene-based detectors is a challenging task. In this work, we utilize the ultrafast laser functionalization of single-layer CVD graphene for highly desirable maskless fabrication of micro- and nanoscale devices. We investigate the optoelectronic response of pristine and functionalized devices under femtosecond and continuous wave lasers irradiation. We demonstrate that the photocurrent generation in p–p+ junctions formed in single-layer graphene is related to the photothermoelectric effect. The photoresponsivity of our laser patterned single-layer graphene junctions is shown to be as high as 100 mA/W with noise equivalent power less than 6 kW/cm2. These results open a path to a low-cost maskless technology for fabrication of graphene-based optoelectronic devices with tunable properties for spectroscopy, signal processing, and other applications.

Individual SWCNT Transistor with Photosensitive Planar Junction Induced by Two‐Photon Oxidation

“…This change is caused by TPO of the carbon surface and is irreversible. [ 30,32 ] The fast charge thermalization leads to the generation of hot carriers [ 33 ] upon fs‐laser pulses in the presence of oxidative species. [ 20 ] It plays a major role in carbon lattice engineering during TPO.…”

Customizing the reduction of individual graphene oxide flakes for precise work function tuning with meV precision

“…Such a system of extraordinary temperature gradients customizable with laser powers, can be exploited as important platforms for a wide range of nanoscale thermodynamics investigations, such as the heat transport across a nanoscale distance and the thermoelectrics of nanomaterials. [30][31][32][33] Precision reduction opens opportunities for custom-designing the properties of GO lms, such as tuning the electrical conductivity, optical band gap and WF. Here we demonstrate that the precisely controlled reduction can be used to ne tune GO's WF.…”

A fast response, self-powered and room temperature near infrared-terahertz photodetector based on a MAPbI3/PEDOT:PSS composite

“…10,[13][14][15] Typically, graphene-based PTE PDs have been studied widely, including single-bilayer interface junction formation, antenna array structure construction, and the preparation of reduced graphene oxide. 12,16,17 In our recent work, we have reported the PTE photoresponses of three-dimensional graphene foam (3D GF) 3 and reduced graphene oxide/CsPbrBr 3 . 18 However, limited by their complex structure and slow response time, graphene-based PTE PDs are still hardly used.…”

“…26 In general, the most effective strategy is to construct a heterojunction using two materials with different Seebeck coefficients to improve the overall PTE response. 16,27 Polymer-based PTE PDs such as poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) devices are receiving increasing attention because of their excellent thermoelectric properties, solution processing capability and high flexibility. [27][28][29][30] The high Seebeck coefficient of up to 436 mV K À1 30 and high electrical conductivity of up to B10 4 S m À1 of PEDOT:PSS 28 can be beneficial for electron transmission in PTE devices.…”