Binary group III-nitride based heterostructures: band offsets and transport properties
TL;DR: In this paper, the growth of non-polar III-nitrides has been an important subject due to its potential improvement on the efficiency of III-nodes-based opto-electronic devices.
Abstract: In the last few years, there has been remarkable progress in the development of group III-nitride based materials because of their potential application in fabricating various optoelectronic devices such as light emitting diodes, laser diodes, tandem solar cells and field effect transistors. In order to realize these devices, growth of device quality heterostructures are required. One of the most interesting properties of a semiconductor heterostructure interface is its Schottky barrier height, which is a measure of the mismatch of the energy levels for the majority carriers across the heterojunction interface. Recently, the growth of non-polar III-nitrides has been an important subject due to its potential improvement on the efficiency of III-nitride-based opto-electronic devices. It is well known that the c-axis oriented optoelectronic devices are strongly affected by the intrinsic spontaneous and piezoelectric polarization fields, which results in the low electron-hole recombination efficiency. One of the useful approaches for eliminating the piezoelectric polarization effects is to fabricate nitride-based devices along non-polar and semi-polar directions. Heterostructures grown on these orientations are receiving a lot of focus due to enhanced behaviour. In the present review article discussion has been carried out on the growth of III-nitride binary alloys and properties of GaN/Si, InN/Si, polar InN/GaN, and nonpolar InN/GaN heterostructures followed by studies on band offsets of III-nitride semiconductor heterostructures using the x-ray photoelectron spectroscopy technique. Current transport mechanisms of these heterostructures are also discussed.
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TL;DR: In this article, the prediction of heterostructure type can be made with good accuracy from the knowledge of the band structure of constituent semiconductors, based on which a classifier model can be trained with an accuracy of $89% using the trained model, a large number (872 number) of unknown heter-structured semiconductor types involving elemental and binary semiconductor.
Abstract: Heterostructures of two semiconductors are at the heart of semiconductor devices with tremendous technological importance. The prediction and designing of semiconductor heterostructures of a specific type is a difficult materials science problem, posing a challenge to experimental and computational investigations. In this study, we first establish that the prediction of heterostructure type can be made with good accuracy from the knowledge of the band structure of constituent semiconductors. Following this, we apply machine learning, built on features characterizing constituent semiconductors, on a known dataset of binary semiconductor heterostructures extended by a synthetic minority oversampling technique. A significant feature of engineering made it possible to train a classifier model predicting the heterostructure type with an accuracy of $89%$. Using the trained model, a large number (872 number) of unknown heterostructure semiconductor types involving elemental and binary semiconductors is theoretically predicted. Interestingly, the developed scheme is found to be extendable to heterojunctions of semiconductor quantum dots.
5 citations
TL;DR: In this article, the electronic structure of (ZnO)1−x (InN) x, (=ZION), which belongs to a novel category of hybrid (II-VI)1 −x (III-V) x alloys, by the interacting quasi-band theory aided by the sp3 tight-binding model of the wurzite structure.
Abstract: We calculated the electronic structure of (ZnO)1−x (InN) x , (=ZION), which belongs to a novel category of hybrid (II–VI)1−x (III–V) x alloys, by the interacting quasi-band theory aided by the sp3 tight-binding model of the wurzite structure. The tight-binding parameters of the irregular bonds (Zn–N and In–O) were estimated by iterating the relevant normal bonds and the absolute atomic levels were corrected by the electron affinities of ZnO and InN. We thus obtained the quasi-band structure of ZION at various concentrations. Across the entire range of concentrations, ZION exhibited a direct energy gap at Γ, and the band-gap energy continuously changes from 0.7 to 3.3 eV with a large band-gap bowing. A particularly, large shift was observed around x = 0.5. The obtained theoretical results imply that ZION (x = 0.1–0.3) is a suitable material for visible-light devices.
5 citations
TL;DR: In this paper, a thermodynamic theory has been proposed to explain the thermal conductivity of InN/GaN heterostructures with and without polarization, which predicts the existence of a transition temperature (Tp) between primary and secondary pyroelectric effect.
5 citations
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TL;DR: AlGaN nanowires are fabricated by molecular beam epitaxy and their field emission properties are investigated by means of an experimental setup using nano-manipulated tungsten tips as electrodes, inside a scanning electron microscope, to explain the observation of modified slope of the Fowler-Nordheim plots in terms of non-homogeneous field enhancement factors due to the presence of protruding emitters.
Abstract: We fabricate AlGaN nanowires by molecular beam epitaxy and we investigate their field emission properties by means of an experimental setup using nano-manipulated tungsten tips as electrodes, inside a scanning electron microscope. The tip-shaped anode gives access to local properties and allows collecting electrons emitted from areas as small as 1$\mu m^2$. The field emission characteristics are analyzed in the framework of Fowler-Nordheim theory and we find a field enhancement factor as high as $\beta$ = 556 and a minimum turn-on field $E_{turn-on}$ = 17 V/$\mu$m for a cathode-anode separation distance d = 500 nm. We show that for increasing separation distance, $E_{turn-on}$ increases up to about 35 V/$\mu$m and $\beta$ decreases to 100 at d = 1600 nm. We also demonstrate the time stability of the field emission current from AlGaN nanowires for several minutes. Finally, we explain the observation of modified slope of the Fowler-Nordheim plots at low fields in terms of non-homogeneous field enhancement factors due to the presence of protruding emitters.
3 citations
Cites background from "Binary group III-nitride based hete..."
...ability 1. Introduction Binary group III-Nitride semiconductors, such as GaN, AlN, and InN are important materials for optoelectronic applications, due to their direct bandgap and doping capabilities [1]. The large breakdown field, the high electron mobility, and their mechanical and thermal robustness, make them optimal candidates also for high power electronics [2]. In the last two decades, one-dim...
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21 Mar 1997
TL;DR: The physics of gallium nitrides and related compounds GaN growth p-Type GaN obtained by electron beam irradiation n-Type GAN p-type GaN InGaN Zn and Si co-doped GaN double-heterostructure blue and blue green LEDs inGaN single-quantum-well structure LEDs room-temperature pulsed operation of laser diodes emission mechanisms of LEDs and LDs room temperature CW operation of InGAN MQW LDs latest results as discussed by the authors.
Abstract: Physics of gallium nitrides and related compounds GaN growth p-Type GaN obtained by electron beam irradiation n-Type GaN p-Type GaN InGaN Zn and Si co-doped InGaN/AlGaN double-heterostructure blue and blue-green LEDs inGaN single-quantum-well structure LEDs room-temperature pulsed operation of laser diodes emission mechanisms of LEDs and LDs room temperature CW operation of InGaN MQW LDs latest results - lasers with self-organized InGaN quantum dots
3,805 citations
TL;DR: In this article, the InGaN multi-quantum-well (MQW) structure was used for laser diodes, which produced 215mW at a forward current of 2.3
Abstract: InGaN multi-quantum-well (MQW) structure laser diodes (LDs) fabricated from III-V nitride materials were grown by metalorganic chemical vapor deposition on sapphire substrates. The mirror facet for a laser cavity was formed by etching of III-V nitride films without cleaving. As an active layer, the InGaN MQW structure was used. The InGaN MQW LDs produced 215 mW at a forward current of 2.3 A, with a sharp peak of light output at 417 nm that had a full width at half-maximum of 1.6 nm under the pulsed current injection at room temperature. The laser threshold current density was 4 kA/cm2. The emission wavelength is the shortest one ever generated by a semiconductor laser diode.
2,100 citations
TL;DR: In this paper, the Schottky barrier heights and band offsets for high dielectric constant oxides on Pt and Si were calculated and good agreement with experiment is found for barrier heights.
Abstract: Wide-band-gap oxides such as SrTiO3 are shown to be critical tests of theories of Schottky barrier heights based on metal-induced gap states and charge neutrality levels. This theory is reviewed and used to calculate the Schottky barrier heights and band offsets for many important high dielectric constant oxides on Pt and Si. Good agreement with experiment is found for barrier heights. The band offsets for electrons on Si are found to be small for many key oxides such as SrTiO3 and Ta2O5 which limit their utility as gate oxides in future silicon field effect transistors. The calculations are extended to screen other proposed oxides such as BaZrO3. ZrO2, HfO2, La2O3, Y2O3, HfSiO4, and ZrSiO4. Predictions are also given for barrier heights of the ferroelectric oxides Pb1−xZrxTiO3 and SrBi2Ta2O9 which are used in nonvolatile memories.
1,947 citations
PARC1
TL;DR: In this article, the group III elements of the semiconducting nitrides have been used for the fabrication of high-efficiency solid-state devices that emit green and blue light.
Abstract: Recent advances in fabrication technologies for the semiconducting nitrides of the group III elements have led to commercially available, high-efficiency solid-state devices that emit green and blue light Light-emitting diodes based on these materials should find applications in flat-panel displays, and blue and ultraviolet laser diodes promise high-density optical data storage and high-resolution printing
1,533 citations