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本文研究AlN作为AlxGa1-xN/GaN插入层引起的电子输运性质的变化, 考虑了AlxGa1-xN和AlN势垒层的自发极化、压电极化对AlxGa1-xN/AlN/GaN双异质结高电子迁移率晶体管(HEMT)中极化电荷面密度、二维电子气(2DEG) 浓度的影响, 分析了AlN厚度与界面粗糙度散射和合金无序散射的关系; 结果表明, 2DEG 浓度、界面粗糙度散射和合金无序散射依赖于AlN层厚度, 插入一层1–3 nm薄的AlN层, 可以明显提高电子迁移率. 相似文献
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Influence of a two-dimensional electron gas on current—voltage characteristics of Al0.3{Ga}0.7 N/GaN high electron mobility transistors 下载免费PDF全文
The J-V characteristics of AltGa1 tN/GaN high electron mobility transistors(HEMTs) are investigated and simulated using the self-consistent solution of the Schro dinger and Poisson equations for a two-dimensional electron gas(2DEG) in a triangular potential well with the Al mole fraction t = 0.3 as an example.Using a simple analytical model,the electronic drift velocity in a 2DEG channel is obtained.It is found that the current density through the 2DEG channel is on the order of 10^13 A/m^2 within a very narrow region(about 5 nm).For a current density of 7 × 10^13 A/m62 passing through the 2DEG channel with a 2DEG density of above 1.2 × 10^17 m^-2 under a drain voltage Vds = 1.5 V at room temperature,the barrier thickness Lb should be more than 10 nm and the gate bias must be higher than 2 V. 相似文献
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A population inversion study of GaAs/AlxGa1-x As three-quantum-well quantum cascade structures is presented. We derive the population inversion condition (PIC) of the active region (AR) and discuss the PICs on different structures by changing structural parameters such as the widths of quantum wells or barriers in the AR. For some instances, the PIC can be simplified and is proportional to the spontaneous emission lifetime between the second and the first excited states, whereas some other instances imply that the PIC is proportional to the state lifetime of the second excited state. 相似文献
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Phase diffusion of a two-component Bose-Einstein condensates:exact and short-time solutions for arbitrary coherent spin state 下载免费PDF全文
We investigate phase diffusion of a two-component
Bose--Einstein condensates prepared initially in arbitrary coherent
spin state |θ0,φ0|. Analytical expression of the
phase-diffusion time is presented for θ0~π/2 case. In
comparison with the symmetrical case (i.e., θ0=π/2), we
find that the diffusion process becomes slow due to the reduced
atom number variance. 相似文献
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The deformation potential and piezoelectric field in nitride GaN/AIN quantum dots (QDs) are investigated in the framework of effective mass approximation (EMA) and finite element method (FEM). The strained fields and piezoelectric characteristics are studied by using FEM for GaN/AIN QDs (GaN embedded in AIN) in the shape of truncated hexagonal pyramids. We presented the calculated results of the electronic states, wave functions, QD strain field distribution and piezoelectric effects in the QDs. Effects of spontaneous and piezoelectric polarization are taken into account in the calculation. The theoretical results are dependent on QD shapes and sizes. Some of them make the GaN/AIN QDs interesting candidates in optoelectronic applications. 相似文献
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