Epitaxial growth and optical properties of semipolar (112¯2) GaN and InGaN∕GaN quantum wells on GaN bulk substrates
Epitaxial growth and optical properties of semipolar (112¯2) GaN and InGaN∕GaN quantum wells on GaN bulk substrates
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DOI：
10.1063/1.2397029
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发表时间：
2006-11
影响因子：
4
通讯作者：
M. Ueda;K. Kojima;M. Funato;Y. Kawakami;Y. Narukawa;T. Mukai
中科院分区：
文献类型：
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作者：
M. Ueda;K. Kojima;M. Funato;Y. Kawakami;Y. Narukawa;T. Mukai
采用金属有机物气相外延技术在半极性（112 <$2）GaN衬底上生长了GaN和InGaN scinGaN多量子阱（MQW）。GaN同质外延层具有原子级平坦表面。光学反射测量揭示了A、B和C激子的偏振各向异性。自由A激子在10 K下的光致发光（PL）光谱中占主导地位，并且伴随着由于中性施主束缚激子而产生的较弱的尖锐双重发射。在GaN同质外延层上生长的InGaN scinGaN MQW涉及快速辐射复合过程。在428 nm处测得的光致发光衰减符合双指数曲线，在10 K下的寿命分别为46和142 ps。这些值是两个数量级短于那些在传统的c-取向量子阱，并归因于减弱的内部电场。由于GaN和MQW晶体的低对称性，其发射沿着[11 00]方向，偏振度分别为0.46和0.69。
GaN and InGaN∕GaN multiple quantum well (MQW) were grown on semipolar (112¯2) GaN bulk substrates by metal organic vapor phase epitaxy. The GaN homoepitaxial layer has an atomically flat surface. Optical reflection measurements reveal polarization anisotropy for the A, B, and C excitons. Free A excitons dominate the photoluminescence (PL) spectrum at 10K and are accompanied by a weaker, sharp doublet emission due to neutral donor-bound excitons. The InGaN∕GaN MQW grown on a GaN homoepitaxial layer involves fast radiative recombination processes. The PL decay monitored at 428nm can be fitted with a double exponential curve, which has lifetimes of 46 and 142ps at 10K. These values are two orders of magnitude shorter than those in conventional c-oriented QWs and are attributed to the weakened internal electric field. The emissions from GaN and MQW polarize along the [11¯00] direction with polarization degrees of 0.46 and 0.69, respectively, due to the low crystal symmetry.