Dynamic Control of High-Range Photoresponsivity in a Graphene Nanoribbon Photodetector

Abstract

Graphene has been demonstrated to be a promising material for optoelectronics and photodetection devices because of its ultra-broadband optical absorption and high carrier mobility. However, its integration with optoelectronic systems has been limited by the zero-bandgap and the lack of a gain mechanism. Herein, we demonstrate a novel photodetector based on the graphene nanoribbons (GRNs) with a sizable bandgap. Utilizing trapping charge at the interface between SiO 2 and lightdoped silicon, an ultrahigh gain of 22,400 has been obtained. Our devices show an enhanced photoresponsivity (~800 AW −1) while the response speed is still fast (up to 10 μs). This photoresponsivity is about two orders of magnitude higher compared to that of a previous graphene-based photodetector. The photodetector exhibits a wide-range tunability via source-drain bias and back gate voltage. Our work addresses key challenges for the photodetectors and potentially provides the desired pathway toward practical application of graphene photodetectors that can be externally manipulated by an electric field with fast response speed and high sensitivity.

Engineering Surface Plasmons in Metal/Nonmetal Structures for Highly Desirable Plasmonic Photodetectors

“…When excited by light, the plasmon induced electromagnetic fields can be confined in graphene/dielectric interfaces and showed plasmons frequency localizing at the MIR to THz region . Note that localized surface plasmons can be produced in patterned graphene nanostructures, such as nanoribbons, , nanodisks, and nanoholes, leading to remarkably enhanced absorption at the resonance wavelength (Figure g). In addition, the plasmonic energy of graphene can be actively controlled by electrical gating because of the easily tunable carrier density of graphene through electrical gating (Figure h). , Therefore, the rational design of plasmonic graphene nanostructure to excite the intrinsic plasmons will be a promising way for boosting light trapping, which enables plasmonic photodetectors to work in the long-wavelength regions.…”

Two-Dimensional Field-Effect Transistor Sensors: The Road toward Commercialization

“…Graphene (Gr), being the most heavily investigated one, has a 2D lattice composed of sp 2 -hybridized carbons and all six-membered rings (i.e., the honeycomb structure, Figure a). , On one hand, π-bonds induced by sp 2 hybridization promote in-plane charge transport in graphene. , On the other hand, the honeycomb structure gives rise to a centrosymmetric Brillouin zone with zero-band gap points between valence and conduction bands (termed “charge neutrality point (CNP)”, also called as “Dirac point”). − In single-layer graphene, the in-plane directions can be defined as “armchair” and “zigzag”. , The armchair/zigzag edge provides graphene with distinct properties including the mobility and coupling effect, which adds functionalities of graphene-based electronics. , The armchair/zigzag edges also increase the difficulty to precisely control the functionalization density on graphene, because the crystalline basal planes are less reactive than the edges . Thus, the literature reports a vast number of methods to achieve a uniform and precise modification of graphene by using covalent bonds or noncovalent intermolecular forces, such as π–π stacking forces, n-hydroxysuccinimide/carbodiimide hydrochloride chemistry, laser-assisted technology, and others.…”

The Photodetectors Based on Lateral Monolayer MoS2/WS2 Heterojunctions

“…Considering the almost half-a-trillion-dollar semiconductor-chip market, two-dimensional (2D) materials are currently one of the most feasible and promising candidates for extending Moore's law [1][2][3][4][5]. As a representative member of the 2D family, transition metal dichalcogenides (TMDs) have been intensively studied due to their distinctive optoelectronic properties and potential applications [6][7][8][9][10][11][12] in photodetection and lightemitting devices [13,14].…”