Polarized infrared reflectance study of free standing cubic GaN grown by molecular beam epitaxy
Polarized infrared reflectance study of free standing cubic GaN grown by molecular beam epitaxy
复制标题
DOI：
10.1016/j.matchemphys.2014.03.008
复制
发表时间：
2014-07
影响因子：
4.6
通讯作者：
S. C. Lee;S. Ng;H. A. Hassan;Z. Hassan;N. Zainal;S. Novikov;C. T. Foxon;A. Kent
中科院分区：
文献类型：
--
作者：
S. C. Lee;S. Ng;H. A. Hassan;Z. Hassan;N. Zainal;S. Novikov;C. T. Foxon;A. Kent
用红外偏振反射技术研究了分子束外延生长的自由立方氮化镓的光学性质。观察到一个很强的RESTRAHLEN带，它揭示了类体光学声子频率。同时，在非共振区域观察到连续的振荡条纹，表明样品由两个介电常数不同的均匀层组成。通过获得在较大入射角下测量的偏振红外反射光谱的一阶导数，在剩余辐射带的边缘识别出额外的声子共振。用基于多振子模型模拟的理论结果验证了观测结果。
Optical properties of free standing cubic gallium nitride grown by molecular beam epitaxy system are investigated by a polarized infrared (IR) reflectance technique. A strong reststrahlen band, which reveals the bulk-like optical phonon frequencies, is observed. Meanwhile, continuous oscillation fringes, which indicate the sample consists of two homogeneous layers with different dielectric constants, are observed in the non-reststrahlen region. By obtaining the first derivative of polarized IR reflectance spectra measured at higher angles of incidence, extra phonon resonances are identified at the edges of the reststrahlen band. The observations are verified with the theoretical results simulated based on a multi-oscillator model.