Study of impurity states in II-VI semiconductor particles by local photon-emission spectroscopy

利用局域光子发射光谱研究 II-VI 族半导体颗粒中的杂质态

基本信息

批准号：
06640449
负责人：
NISHITANI Ryusuke
金额：
$ 1.34万
依托单位：
Kyushu Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640449/
关键词：
STM photon emission scanning tunneling microscope local electronic structure fine particle surface plasmon nanoscale digital control 局所電子状態スペクトロスコピー II-VI族半導体プラズマスッパタリング STS

项目摘要

1.For the study of the local electronic structure of the surfaces and the microclusters, we have made a digital controlled UHV-STM which is able to record 2-dimensional map of the intensity of the photon emitted from the STM tunnel junction. An image of the photon map is recorded simultaneously with the measurements of a topography image by STM and the STS measurements. The spectral resolved photon-maps can also be obtained by using an optical band pass filter with the band width of about 50 nm and the center of the wave length of 700 and 650 nm. This apparatus is emplyed to observe the STM induced photon-maps for the film of the noble metal particles (Au and Ag) on the graphite surface. We have measured the photon images for various morphology of the film to investigate the correlation between the photon maps and the morphology of the films. We have observed that the photon map is dependent on the wave length of the collected light. We have found that the photon spectra is closely related with the geometry of the STM tip and the metal particles. The change in the spectral resolved photon map is explained in terms of the effect of the curvature radius of the STM tip on the photon spectra.2.We have studied the optical properties of the CdS microclustes. The microclustes of CdS microclusters in various sizes ranging from 1 to 2nm are prepared by precipitation technique.We have observed the size-dependnet absorption spectra for the CdS microclusters. The absorption edge for the CdS clusters increases in energy with the decrease in the cluster size. This observation is explained by the quantum size effect on the electronic levels of CdS microclustes.

1.为了研究表面和微团簇的局部电子结构，我们制作了数控UHV-STM，它能够记录从STM隧道结发射的光子强度的二维图。光子图的图像与 STM 和 STS 测量的形貌图像的测量同时记录。光谱分辨光子图也可以通过使用带宽约为50 nm、波长中心为700 和650 nm 的光学带通滤波器来获得。该装置用于观察石墨表面贵金属颗粒（Au和Ag）薄膜的STM诱导光子图。我们测量了薄膜各种形态的光子图像，以研究光子图与薄膜形态之间的相关性。我们观察到光子图取决于所收集光的波长。我们发现光子光谱与STM尖端和金属颗粒的几何形状密切相关。光谱分辨光子图的变化可以通过STM尖端曲率半径对光子光谱的影响来解释。2.研究了CdS微团簇的光学性质。采用沉淀技术制备了1~2nm各种尺寸的CdS微团簇。我们观察到了CdS微团簇的尺寸依赖性吸收光谱。 CdS 团簇的吸收边能量随着团簇尺寸的减小而增加。这一观察结果可以通过 CdS 微簇电子能级的量子尺寸效应来解释。