Gap‐Mode Plasmon‐Induced Photovoltaic Effect in a Vertical Multilayer Graphene Homojunction

Abstract

Gap‐mode plasmons that occur between metallic nanoparticles and metallic films separated by a thin spacer have been widely studied in the field of nano‐optics and plasmonics for enhancing the light–matter interaction of graphene and other two‐dimensional (2D) materials. However, efficient photovoltaic devices using such gap‐mode plasmons have not been achieved because of structural difficulties. Here, a gap‐mode plasmon‐induced asymmetric vertical homojunction photovoltaic device using multilayer graphene is presented. In this structure, the multilayer graphene acts both as a photo‐carrier generation layer and as a spacer for the gap‐mode plasmon. The optical absorption of graphene is further enhanced by the presence of gap‐mode plasmons, and the photoresponse time is extremely short because of the atomically short channel lengths across the vertical direction. The wavelength dependence of the gap‐mode plasmon is also investigated for three devices with different metal electrodes by photocurrent measurement at five different wavelengths and numerical simulations. The device strategies implemented in this work can enhance the performance of graphene‐based vertical photonic devices and can be applied to other 2D materials‐based photonic devices.

Applying 2DEG in High‐Performance Mid‐Infrared Photodetection

“…Although our detector employs a lateral device structure (like a photoconductive detector), the photogenerated electron relaxation path from the PbTe layer to the 2DEG interface is extremely short, similar to the vertically stacked heterostructures composed of 2D layered materials. [21,39] Furthermore, the high mobility of 2DEG at the CdTe/PbTe interface yields a rapid photoresponse, which is much superior to those of the 2D layered heterostructures. [21,27,34,40,41] The transient photoelectric response measured at two representative temperatures is shown in Figure 2d,e with ≈2.5 μm laser pulse excitation.…”

Spectral Tuning of a Nanoparticle-on-Mirror System by Graphene Doping and Gap Control with Nitric Acid

“…This is because the light is confined within dimensions similar to the material of atomic thickness. This gives rise to a pathway for much stronger light–matter interaction for 2D materials, allowing much deeper exploration into their optical properties. − Another advantage of utilizing 2D materials in these systems is that their thicknesses are well known and constant at the monolayer limit. This constant gap thickness can be useful in keeping the gap size fixed while monitoring the other changes in the plasmonic system …”

“…A well-explored 2D material is graphene, the thinnest of the 2D materials, with a thickness of 0.34 nm. ,, Graphene has many unique properties, including its high electrical conductivity and its high chemical stability. − Graphene has a tunable dielectric response that can be modified by doping both chemically and electrically. This can be manipulated for a wide variety of applications, including hyperlenses, metacouplers, photovoltaic devices, and super-resolution imaging and sensing. ,, Many techniques have been developed to allow for the growth of a large surface area and a high-quality monolayer film, such as chemical vapor deposition, flame synthesis, and pulsed laser deposition . Many studies have explored the coupling of graphene to plasmonic structures, mostly in the infrared region.…”

“…This can be manipulated for a wide variety of applications, including hyperlenses, metacouplers, photovoltaic devices, and super-resolution imaging and sensing. 18,26,27 Many techniques have been developed to allow for the growth of a large surface area and a high-quality monolayer film, such as chemical vapor deposition, flame synthesis, and pulsed laser deposition. 28 Many studies have explored the coupling of graphene to plasmonic structures, mostly in the infrared region.…”

Review—A Review of Advanced Electronic Applications Based on Carbon Nanomaterials

“…Gap-mode plasmons occur between metallic nanoparticles and metallic films separated by a thin spacer, and have been widely studied in the field of nano-optics and plasmonics for enhancing the light matter interactions of graphene and other 2D materials. 183 However, efficient photovoltaic devices which use such gap-mode plasmons have not been attained due to structural difficulties. K. J. Lee et al presented a photovoltaic device using multilayer graphene with a gap-mode plasmon-induced asymmetrical vertical homojunction.…”