The assessment of emission mechanism in GaN-based nano-structures by scanning near-field optical microscopy

通过扫描近场光学显微镜评估 GaN 基纳米结构的发射机制

基本信息

批准号：
15206033
负责人：
KAWAKAMI Yoichi
金额：
$ 25.79万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

The purpose of this project is to assess and/or control the radiative recombination processes in InGaN/GaN-based quantum wells by employing photoluminescence (PL) mapping with scanning near field optical microscopy (SNOM), by which dramatic improvement of emission efficiency as well as the extension of operatable wavelength can be achieved in emitters such as light emitting diodes (LEDs), laser diodes (LDs) and new phosphors. Our approach is to fabricate micro/nano structures for multi-wavelength lighting, to elucidate fundamental optical properties, and to make a positive feedback to future device structures. Main results are summarized as shown below.(1)We have developed the experimental technique by combining the SNOM-PL with atomic force microscopy (AFM), where the correlation was clearly revealed between dislocations and weak emission regions. Moreover, time-resolved PL measurements with this method showed the dynamical behavior of photo-generated carriers and/or excitons in potential fluctuations. It was found that the pathway to nonradiative recombination centers is effectively hindered by the compositional modulation around the dislocations, so that the carrier diffusion is spatially unisotropic process.(2)We have proposed the re-growth technique, where well-established c-oriented GaN is used as a seed. It has been demonstrated that the growth on c-oriented GaN patterned with a stripe along the [11^^-00] direction forms (0001), <112^^-2>, and <112^^-0> facets and that the QW on the <112^^-2> facet involves weaker electric fields and has a higher PL efficiency, compared with conventional c-oriented InGaN/GaN QWs. Moreover, rainbow color PL covering the entire visible range has been achieved from InGaN/GaN QWs on the <112^^-2> facets with a few micron-width.

该项目的目的是通过采用光致发光（PL）映射（PL）映射（SNOM）来评估和/或控制基于Ingan/GAN的量子孔中的辐射重组过程，通过扫描（SNOM），通过这些扫描，通过这些绘制，可在emitters timing（Emitters）中急剧提高发射效率以及可操作效率的扩展（延伸）。（LDS）和新的磷酸盐。我们的方法是为多波长照明制造微/纳米结构，以阐明基本的光学特性，并对将来的设备结构产生积极的反馈。如下所示，总结了主要结果。（1）我们通过将SNOM-PL与原子力显微镜（AFM）相结合，开发了实验技术，在该方法之间，在错位和弱发射区域之间清楚地揭示了相关性。此外，使用此方法的时间分辨PL测量结果显示了潜在波动中光生成的载体和/或激子的动态行为。据研究发现，非放射性重组中心的途径受到围绕错位的组成调节的有效阻碍，因此载体扩散在空间上是单一的一致性过程。（2）我们提出了重新增长的技术，其中已建立了成熟的C型C型GAN作为种子。已经证明，沿[11 ^^ - 00]方向（0001），<112 ^^ - 2>>和<112 ^^ - 0> <112 ^^ -2> facet上的QW涉及较弱的电场，并且具有较高的PL效率的QW与常规c-concountional c-Q-n Ingen Ingign Inigient相比。此外，从<112 ^^ - 2> facets上的彩虹颜色覆盖了整个可见范围的彩虹颜色，并具有几微宽度。