Ultrastrong Terahertz Emission from InN Nanopyramids on Single Crystal ZnO Substrates

Abstract

The creation of high efficiency and room temperature terahertz (THz) emitters has long been expected in both scientific and industrial communities. Despite the recent progress in THz source such as quantum cascade lasers, high efficiency THz emitters capable of operating at room temperature are still elusive. Indium nitride (InN), a narrow bandgap semiconductor, has emerged as a promising THz emitter due to its unique electronic properties. However, the efficiency of InN THz emitters reported up to now is still far from theoretically predicted because of inadequately engineered electrical conduction and radiative coupling. In this study, the authors report a novel, high performance THz emitting structure consisting of nanoengineered InN micro/nanopyramid arrays on a single crystal zinc oxide (ZnO) substrate. With improved electronic conduction from Zn diffusion induced doping and enhanced radiation coupling benefiting from uniquely structured geometry, the InN nanopyramids yielded THz emission intensity is close to an order of magnitude stronger than that of p‐type indium arsenide (InAs). These findings prove that InN is a promising THz material and of wide importance in material science, optical engineering sectors, etc.

Strong tribo-piezoelectric effect in bilayer indium nitride (InN)

“…The considered InN nanogenerator is a promising candidate in energy harvesting applications, especially for low-power electronics and self-powered sensors. In recent times, there have been tremendous improvements and investigations to fabricate InN based devices 71 , for instance, thin-film transistors 72 , lasers 73 , photovoltaic converters 74 , photodetectors 75 , and a number of terahertz-range devices 76 . Moreover, InN based nanowire 77 and other structures 78 , 79 are also getting improved day by day.…”

Graphene‐Nanorod Enhanced Quasi‐Van Der Waals Epitaxy for High Indium Composition Nitride Films

“…Over the past few years, nitrides, specifically GaN and Ga-rich InGaN, are proven to be the most important and indispensable materials for the fabrication of light emitters in the blue and near ultraviolet spectral regions. [1,2] Due to the bandgap tunability of InGaN alloy system, there also has been extensive research to extend the applications of indium (In)-rich InGaNbased semiconductor devices such as fullcolor displays, high-efficiency photovoltaic solar cells, fiber optics, and thermoelectric and nonlinear optical devices, [3][4][5][6][7][8] in which the GaN is commonly used as the template to grow In-rich InGaN films. However, the development of nitride films with high In composition remains challenging in terms of phase separation, InN decomposition, and relatively high vapor pressure.…”

Metalorganic chemical vapor deposition of InN quantum dots and nanostructures

“…In addition, as MOCVD is typically used to grow the GaN templates and other device layers, such that growing the InN QDs by MOCVD would prevent the need to use multiple growth techniques for a single device stack. In addition to the two main growth techniques, epitaxial InN nanostructures have also been grown by various other methods including plasma-assisted MOCVD 33 , gold-assisted nanowire growth 34,35 , plasma aerotaxy 36 , oblique angle deposition method 37 , chemical beam epitaxy 38 , and chemical vapor deposition [39][40][41][42][43] . Although MOCVD has the potential to be the preferred growth option for InN QDs due to scalability and fast growth rates, the high growth temperatures (>1000 °C) typical for high-quality GaN growth pose challenges for the incorporation of InN into device stacks.…”