Investigating crystalline-polarity-dependent electronic structures of GaN by hard x-ray photoemission and ab-initio calculations
Investigating crystalline-polarity-dependent electronic structures of GaN by hard x-ray photoemission and ab-initio calculations
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DOI：
10.1063/1.4934842
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发表时间：
2015-10-26
影响因子：
4
通讯作者：
Ohashi, Naoki
中科院分区：
文献类型：
--
作者：
Ohsawa, Takeo;Ueda, Shigenori;Ohashi, Naoki
利用不同线极化的软、硬X射线，用光电子能谱(PES)研究了氮化镓(GaN)的电子结构与晶体极性的关系。与(000(1)Over bar)表面相比，位于价带(Vb)最大值附近的峰在(0001)面上增强，而与光子能量无关。通过从头计算得到的VB态密度与观测到的VB-PES谱的比较表明，晶体的极性依赖关系与Ga4p和N2p态有关。晶体极性相关的Vb特征最合理的来源是GaN c轴自发极化引起的p(Z)轨道上电子的光电子发射现象。(C)2015 AIP出版有限责任公司。
Crystalline-polarity-dependent electronic structures of gallium nitride (GaN) were studied by photoemission spectroscopy (PES) using soft and hard x-rays with different linear polarizations. A peak located near the valence band (VB) maximum was enhanced for a (0001) surface compared with that for a (000 (1) over bar) surface regardless of photon energy. Comparison of the VB density of states obtained by ab-initio calculations with the observed VB-PES spectra indicates that the crystalline-polarity dependence is associated with the Ga 4p and N 2p states. The most plausible origin of the crystalline-polarity-dependent VB feature is based on the photoemission phenomena of electrons in the p(z)-orbitals due to spontaneous electric polarization along the c-axis of GaN. (C) 2015 AIP Publishing LLC.