Optical Properties of InGaN/GaN QW with the Same Well-Plus-Barrier Thickness

Crystals

Huan Xu¹  Xin Hou¹  Yang Mei¹  Lan Chen¹  Baoping Zhang¹ 

[1] Laboratory of Micro/Nano-Optoelectronics, Department of Microelectronics and Integrated Circuits, Xiamen University, Xiamen 361005, China;

关键词: InGaN/GaN multiple quantum wells;    localization states well thickness;    barrier thickness;    photoluminescence;   

DOI  :  10.3390/cryst12010114

来源: DOAJ

【 摘 要 】

Optical properties of wurtzite violet InGaN/GaN quantum well (QW) structures, with the same well-plus-barrier thickness, grown by metal-organic chemical vapor deposition (MOCVD) on c-plane sapphire substrates, were investigated using temperature-dependent photoluminescence (TDPL) and excitation-power-dependent photoluminescence (PDPL). Two samples were compared: one had a thicker well (InGaN/GaN 3/5 nm); the other had a thicker barrier (InGaN/GaN 2/6 nm). It was found that the GaN barrier thickness in the InGaN/GaN MQWs plays an important role in determining the optical characteristics of the MQWs. The peak energy of the two samples varied with temperature in an S-shape. The thicker-barrier sample had a higher turning point from blueshift to redshift, indicating a stronger localization effect. From the Arrhenius plot of the normalized integrated PL intensity, it was found that the activation energy of the nonradiative process also increased with a thicker barrier thickness. The radiation recombination process was dominated in the sample of the thicker barrier, while the non-radiation process cannot be negligible in the sample of the thicker well.

【 授权许可】

Unknown