GaN light-emitting diodes with an Al-coated graphene layer as a transparent electrode

Abstract

We fabricated GaN light-emitting diodes with a layer of graphene as a transparent electrode. A 3-nm-thick Al layer was deposited on the graphene layer by electron-beam evaporation. This Al layer plays an important role in protecting the graphene layer during the device fabrication process. Moreover, this Al layer can also enhance the light emission of GaN light-emitting diodes through the investigation of electroluminescence spectra. The significantly improved light emission is attributed to the current expansion, the enhanced plasmonic density of states, and the decreased nonradiative recombination rate.

Influence of Substrate Microstructure on the Transport Properties of CVD-Graphene

“…There is a strong economically driven demand for alternative inexpensive transparent contacts to optoelectronic devices. Due to its high transparency, flexibility, low cost, and availability of large area production, graphene obtained by chemical vapor deposition (CVD) is considered to be a serious candidate to replace indium tin oxide (ITO). − Thanks to the possibility to transfer graphene on structured surfaces , and to its high conductivity (a typical sheet resistance on a millimeter scale is 0.15–0.45 kΩ/sq , ). CVD-graphene has recently been applied as a transparent contact to three-dimensional nanostructures based on nanowire arrays, ,, nanopillars, , micropyramids, , and single nanostructures. − In particular, graphene has been employed in nanostructured light-emitting diodes (LEDs) based on GaN micropyramids in view of solid state lightning applications. , Moreover, the mechanical flexibility of graphene also enables its use as a contact for flexible light sources. ,, …”

Direct growth of multilayer graphene by precipitation using W capping layer

“…Since the unique properties of graphene layers mechanically peeled from highly oriented pyrolytic graphite were first reported, [1][2][3][4] there have been expectations that graphene would find applications in a wide range of fields, such as high-speed transistors, [5][6][7][8][9][10] electrical wiring, 11,12) and transparent electrodes. [13][14][15] After the initial discovery of the mechanical peeling method, 1) several other methods, such as SiC surface decomposition 16) and chemical vapor deposition (CVD), [17][18][19][20] were proposed for growing graphene. The latter method attracted significant attention because it offered the possibility of growing high-quality graphene over large areas.…”

Two-dimensional hexagonal V2O nanosheet and nanoribbons

“…T wo-dimensional (2D) materials have historically been one of the most extensively studied types of materials due to the wealth of unusual physical phenomena exhibited when charge and heat transports are confined to a plane. [1][2][3][4][5][6][7][8][9] Single-layer graphene, which was discovered in 2004 by Novoselov and Geim, has shown the possibility of exfoliating stable single-atom or single-polyhedral-thick 2D materials from van der Waals (vdW) solids, and more importantly, these materials can exhibit unique and fascinating physical properties. 10,11) Recently, some novel singlelayer-thick materials that were initially considered to exist only in the realm of theory, including hexagonal BN, 12) silicene, 13,14) phosphorene, 15) transition-metal dichalcogenides, 16,17) and so on, have been synthesized experimentally.…”