材料科学
异质结
蓝宝石
宽禁带半导体
费米气体
光电子学
极化(电化学)
氮化镓
图层(电子)
凝聚态物理
电子
光学
纳米技术
化学
物理
物理化学
量子力学
激光器
作者
S. Heikman,S. Keller,Yuan Wu,James S. Speck,Steven P. DenBaars,Umesh K. Mishra
摘要
The influence of AlGaN and GaN cap layer thickness on Hall sheet carrier density and mobility was investigated for Al0.32Ga0.68N/GaN and GaN/Al0.32Ga0.68N/GaN heterostructures deposited on sapphire substrates. The sheet carrier density was found to increase and saturate with the AlGaN layer thickness, while for the GaN-capped structures it decreased and saturated with the GaN cap layer thickness. A relatively close fit was achieved between the measured data and two-dimensional electron gas densities predicted from simulations of the band diagrams. The simulations also indicated the presence of a two-dimensional hole gas at the upper interface of GaN/AlGaN/GaN structures with sufficiently thick GaN cap layers. A surface Fermi-level pinning position of 1.7 eV for AlGaN and 0.9–1.0 eV for GaN, and an interface polarization charge density of 1.6×1013–1.7×1013 cm−2, were extracted from the simulations.
科研通智能强力驱动
Strongly Powered by AbleSci AI