Additional phonon modes and close satellite valleys crucialfor electron transport in hexagonal gallium nitride

2004 ◽  
Vol 85 (4) ◽  
pp. 609-611 ◽  
Author(s):  
R. Brazis ◽  
R. Raguotis
Keyword(s):  
Gallium Nitride ◽  
Electron Transport ◽  
Phonon Modes ◽  
Close Satellite

Solving Nongray Boltzmann Transport Equation in Gallium Nitride

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Ajit K. Vallabhaneni ◽  
Liang Chen ◽  
Man P. Gupta ◽  
Satish Kumar
Keyword(s):  
Gallium Nitride ◽  
Transport Equation ◽  
Thermal Transport ◽  
Hot Spot ◽  
Boltzmann Transport Equation ◽  
Significant Loss ◽  
Computational Time ◽  
Boltzmann Transport ◽  
Phonon Modes ◽  
Fourier Model

Several studies have validated that diffusive Fourier model is inadequate to model thermal transport at submicron length scales. Hence, Boltzmann transport equation (BTE) is being utilized to improve thermal predictions in electronic devices, where ballistic effects dominate. In this work, we investigated the steady-state thermal transport in a gallium nitride (GaN) film using the BTE. The phonon properties of GaN for BTE simulations are calculated from first principles—density functional theory (DFT). Despite parallelization, solving the BTE is quite expensive and requires significant computational resources. Here, we propose two methods to accelerate the process of solving the BTE without significant loss of accuracy in temperature prediction. The first one is to use the Fourier model away from the hot-spot in the device where ballistic effects can be neglected and then couple it with a BTE model for the region close to hot-spot. The second method is to accelerate the BTE model itself by using an adaptive model which is faster to solve as BTE for phonon modes with low Knudsen number is replaced with a Fourier like equation. Both these methods involve choosing a cutoff parameter based on the phonon mean free path (mfp). For a GaN-based device considered in the present work, the first method decreases the computational time by about 70%, whereas the adaptive method reduces it by 60% compared to the case where full BTE is solved across the entire domain. Using both the methods together reduces the overall computational time by more than 85%. The methods proposed here are general and can be used for any material. These approaches are quite valuable for multiscale thermal modeling in solving device level problems at a faster pace without a significant loss of accuracy.

A detailed characterization of the transient electron transport within zinc oxide, gallium nitride, and gallium arsenide

2012 ◽  
Vol 112 (12) ◽  
pp. 123722 ◽  
Author(s):  
Walid A. Hadi ◽  
Shamsul Chowdhury ◽  
Michael S. Shur ◽  
Stephen K. O'Leary
Keyword(s):  
Gallium Arsenide ◽  
Zinc Oxide ◽  
Gallium Nitride ◽  
Electron Transport ◽  
Detailed Characterization

NANOPOROUS GALLIUM NITRIDE THROUGH ANISOTROPIC METAL-ASSISTED ELECTROLESS PHOTOCHEMICAL WET ETCHING TECHNIQUE

2016 ◽  
Vol 23 (02) ◽  
pp. 1550106 ◽  
Author(s):  
R. PERUMAL ◽  
Z. HASSAN
Keyword(s):  
Gallium Nitride ◽  
Wet Etching ◽  
Scanning Electron Micrographs ◽  
Photoluminescence Intensity ◽  
Phonon Modes ◽  
Porous Network ◽  
Etching Technique ◽  
Porous Nanostructures ◽  
Enhanced Photoluminescence ◽  
Potential Applications

Nanoporous gallium nitride (GaN) has many potential applications in light-emitting diodes (LEDs), photovoltaics, templates and chemical sensors. This article reports the porosification of GaN through UV enhanced metal-assisted electroless photochemical wet etching technique using three different acid-based etchants and platinum served as catalyst for porosification. The etching process was conducted at room temperature for a duration of 90[Formula: see text]min. The morphological, structural, spectral and optical features of the developed porous GaN were studied with appropriate characterization techniques and the obtained results were presented. Field emission scanning electron micrographs exhibited the porosity nature along with excellent porous network of the etched samples. Structural studies confirmed the mono crystalline quality of the porous nanostructures. Raman spectral analyzes inferred the presenting phonon modes such as E2 (TO) and A1 (LO) in fabricated nanoporous structures. The resulted porous nanostructures hold the substantially enhanced photoluminescence intensity compared with the pristine GaN epitaxial film that is interesting and desirable for several advances in the applications of Nano-optoelectronic devices.

Experimental investigation of electron transport properties of gallium nitride nanowires

2008 ◽  
Vol 104 (2) ◽  
pp. 024302 ◽  
Author(s):  
Abhishek Motayed ◽  
Albert V. Davydov ◽  
S. N. Mohammad ◽  
John Melngailis
Keyword(s):  
Experimental Investigation ◽  
Gallium Nitride ◽  
Electron Transport ◽  
Transport Properties ◽  
Electron Transport Properties
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