利用热反射、光致发光和无接触电反射光谱研究 AlGaN/GaN 异质结构的能带边缘结构和内置电场。

Optical investigation of band-edge structure and built-in electric field of AlGaN/GaN heterostructures by means of thermoreflectance, photoluminescence, and contactless electroreflectance spectroscopy.

机构信息

Graduate Institute of Engineering and Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.

出版信息

Opt Lett. 2009 Dec 1;34(23):3604-6. doi: 10.1364/OL.34.003604.

DOI:10.1364/OL.34.003604

PMID:19953134

Abstract

The band-edge property and built-in electric fields of two different Al(x)Ga(1-x)N/GaN(AlGaN/GaN) heterostructures (HSs) with and without an additional AlGaN inserted layer were studied by thermoreflectance (TR), photoluminescence (PL), and contactless electroreflectance (CER) techniques. The PL spectra characterize the band-edge luminescence property of GaN. Free exciton transitions of AlGaN and GaN were probed experimentally by TR. Prominent Franz-Keldysh oscillations (FKOs) of GaN and the opposite FKO phase of AlGaN were simultaneously detected by the additional AlGaN inserted sample with CER owing to the enhancement effect of built-in electric fields of GaN and AlGaN with the same polarity direction. Optoelectronics properties of the two HSs were characterized by the experimental analyses.

摘要

通过热反射（TR）、光致发光（PL）和无接触电反射（CER）技术研究了具有和不具有附加 AlGaN 插入层的两种不同 Al(x)Ga(1-x)N/GaN（AlGaN/GaN）异质结构（HS）的能带边缘性质和内置电场。PL 光谱特征化了 GaN 的能带边缘发光性质。TR 实验探测到了 AlGaN 和 GaN 的自由激子跃迁。由于 GaN 和 AlGaN 的内置电场具有相同的极性方向，因此通过附加的 AlGaN 插入样品，同时检测到 GaN 的明显 Franz-Keldysh 振荡（FKOs）和 AlGaN 的相反 FKOs 相位。通过实验分析，对两个 HS 的光电性能进行了表征。