GHz Electroluminescence Modulation in Nanoscale Subwavelength Emitters

Abstract

We investigate light emission from nanoscale point-sources obtained in hybrid metal-GaAs nanowires embedding two sharp axial Schottky barriers. Devices are obtained via the formation of Ni-rich metallic alloy regions in the nanostructure body thanks to a technique of controlled thermal annealing of Ni/Au electrodes. In agreement with recent findings, visible-light electroluminescence can be observed upon suitable voltage biasing of the junctions. We investigate the time-resolved emission properties of our devices and demonstrate an electrical modulation of light generation up to 1 GHz. We explore different drive configurations and discuss the intrinsic bottlenecks of the present device architecture. Our results demonstrate a novel technique for the realization of fast subwavelength light sources with possible applications in sensing and microscopy beyond the diffraction limit.

High‐Speed Electroluminescence Modulation in Monolayer WS2

“…In general, EL from unipolar devices based on semiconductor–metal junctions results from radiative recombination of electron–hole pairs by carriers injected from a metal into a semiconductor through a Schottky barrier. [ 5,28 ] Similarly, EL from our devices is generated by radiative recombination between electrons in the WS 2 layer and holes injected from graphene when a bias voltage is applied. Holes from graphene below threshold are blocked by the top h‐BN tunnel barrier.…”

“…A number of photonic materials such as organic materials, semiconducting quantum dots, and nanowires have been studied and used as nanoscale light sources. [1][2][3][4][5] Achieving high electrical bandwidth and fast modulation speed has, however, remained a fundamental challenge. [2] Recently, 2D materials have shown exciting properties for optoelectronic applications.…”

Electrostatic Control of the Thermoelectric Figure of Merit in Ion‐Gated Nanotransistors

“…[ 5 ] For all these applications semiconducting nanowires have attracted much interest owing to their versatility and unique properties such as their high aspect ratio and ease of realization both for homogeneous nanostructures and heterostructures. These properties have made them promising for thermoelectrics [ 6–9 ] and nano‐electronics, [ 10–13 ] as well as iontronic nanodevices, [ 14–17 ] optoelectronics, [ 18,19 ] sensing [ 20–22 ] and quantum computing. [ 23,24 ]…”

“…[5] For all these applications semiconducting nanowires have attracted much interest owing to their versatility and unique properties such as their high aspect ratio and ease of realization both for homogeneous nanostructures and heterostructures. These properties have made them promising for thermoelectrics [6][7][8][9] and nano-electronics, [10][11][12][13] as well as iontronic nanodevices, [14][15][16][17] optoelectronics, [18,19] sensing [20][21][22] and quantum computing. [23,24] In the quest for high-efficiency thermoelectric materials, a relevant parameter to be taken into account is the figure of merit ZT = σS 2 T/κ, where σ is the electrical conductivity, κ is the thermal conductivity, and S is the material-dependent Seebeck coefficient.…”

Conductometric Sensing with Individual InAs Nanowires

“…III-V semiconductor nanowires are well established as a suitable platform for different fields of nanoscience and nanotechnology, including thermoelectrics [35,36], signal transduction [37,38], nanoelectronics, optoelectronics, and plasmonics [39,40,41,42]. Recently, nanowire-based sensing applications have gained enormous interest: InAs NWs, both individual and in array configuration, are considered as promising building blocks for the realization of gas sensors due to their easy growth mechanism, to the high value of the electron mobility and to the likely presence of a surface accumulation layer, which makes them particularly sensitive to the surface state dynamics and the environment [30,43,44,45].…”