Effects of piezoelectric fields on optoelectronic properties of InGaN/GaN quantum-well light-emitting diodes prepared on nonpolar (1 0 (1)over-bar 0) and semipolar (1 1 (2)over-bar 2) orientations
Effects of piezoelectric fields on optoelectronic properties of InGaN/GaN quantum-well light-emitting diodes prepared on nonpolar (1 0 (1)over-bar 0) and semipolar (1 1 (2)over-bar 2) orientations
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DOI：
10.1088/0022-3727/42/13/135106
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发表时间：
2009-07-07
影响因子：
3.4
通讯作者：
DenBaars, Steven P.
中科院分区：
文献类型：
--
作者：
Masui, Hisashi;Asamizu, Hirokuni;DenBaars, Steven P.
本文研究了InGaN/GaN量子阱（QW）发光二极管（led）的光学和电学特性。样品在非极性（10 (1)/ bar 0）和半极性（11 (2)/ bar 2）取向上制备。采用电偏应用光致发光作为表征技术。研究证实，在非极性led中，反向光电流饱和发生在0 V左右，而在（11 1 (2)/ bar 2）定向led中，反向光电流饱和发生在正电压下，而我们之前的研究发现（0 00 1）定向led中存在负电压（Masui et al . 2008 J. Phys）。D::。物理学报41（165105）。这些结果表明，（1 1 (2)/ bar 2）取向InGaN/GaN量子阱的压电场方向与内置场方向相同。在（11 1 (2)/ bar 2）取向QW结构中，压电场强估计为-0.3 MV cm（-1）。LED样品的光致发光和电致发光的光谱比较显示，单量子w LED的光谱差异不显著。
Optical and electrical characteristics of InGaN/GaN quantum-well (QW) light-emitting diodes (LEDs) are the subjects of this study. Samples were prepared on nonpolar (1 0 (1) over bar 0) and semipolar (1 1 (2) over bar 2) orientations of bulk GaN substrates. Electrical-bias-applied photoluminescence was employed as a characterization technique. It was confirmed that saturation of reverse photocurrent occurred around 0 V in nonpolar LEDs and at positive voltages in (1 1 (2) over bar 2)-oriented LEDs, while our previous study found negative voltages in (0 0 0 1)-oriented LEDs (Masui et al 2008 J. Phys. D: Appl. Phys. 41 165105). These results indicated that (1 1 (2) over bar 2)-oriented InGaN/GaN QWs experience piezoelectric fields being in the same direction as the built-in field. Piezoelectric field intensity was estimated to be -0.3 MV cm(-1) in the (1 1 (2) over bar 2)-oriented QW structure. Spectral comparison between photoluminescence and electroluminescence of the LED samples exhibited a tendency that spectral differences were insignificant in single-QW LEDs.