Near‐field photoluminescence study in violet light emitting InGaN single quantum well structures
Near‐field photoluminescence study in violet light emitting InGaN single quantum well structures
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DOI：
10.1002/pssc.200461580
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发表时间：
2005-05
期刊：
影响因子：
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通讯作者：
A. Kaneta;D. Yamada;Giichi Marutsuki;Y. Narukawa;T. Mukai;Y. Kawakami
中科院分区：
文献类型：
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作者：
A. Kaneta;D. Yamada;Giichi Marutsuki;Y. Narukawa;T. Mukai;Y. Kawakami
利用扫描近场光学显微镜（SNOM）研究了室温下InGaN单量子阱结构的紫光光致发光（PL）谱的空间分布。在照明收集模式下，PL强度和PL峰值波长之间存在明显的相关性，在低能带发射区观察到较强的PL。然而，在低能区也出现了直径约为几百nm的暗点。此外，具有200 nm的空间分辨率的多模SNOM-PL揭示了I-C模式和照明（I）模式之间的PL强度图像的差异与发射蓝光的InGaN-SQW相比不是那么大。这些研究结果表明，穿线位错作为非辐射复合中心的紫色样品不像蓝色的，和扩散的长度，这些中心是大于本地化的中心，导致辐射复合。此外，在外延横向过度生长（ELO）GaN模板上生长的紫色样品中，已在空间上确定了源于点缺陷的非辐射复合中心。（© 2005 WILEY-VCH Verlag GmbH & Co. KGaA，魏因海姆）
Spatial distribution of photoluminescence (PL) spectra has been assessed in violet light emitting InGaN single-quantum-well (SQW) structures by employing a scanning near-field optical microscope (SNOM) at room temperature. Clear correlation has been found between PL intensity and PL peak wavelength under illumination collection (I-C) mode, where strong PL was observed in the area emitting at lower energy bands. However, dark spots having diamter of about a few hundreds nm appeared also in lower energy region. Moreover, multi-mode SNOM-PL with a spatial resolution of 200 nm revealed that the difference of PL-intensity image between I-C mode and illumination (I) mode is not so large comparing with a blue light emitting InGaN-SQW. These findings suggest that threading dislocations act as nonradiative recombination centers in the violet sample unlike blue ones, and that the diffusion length to such centers is larger than that to localized centers leading to radiative recombination. Furthermore, nonradiative recombination centers originating from point defects have been spatially identified in the violet sample grown on epitaxially laterally overgrown (ELO) GaN template. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)