Study on structural fluctuations in amorphous semiconductors by micro-light scattering

微光散射研究非晶半导体结构涨落

• 批准号: 11640317
• 负责人: INOUE Koichi
• 金额: $ 0.64万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640317/
• 关键词: light scattering; amorphous materials; micro-optics; lattice vibration; Raman scattering

While long-range order is lacked in amorphous semiconductors, short-range order such as bond-length and bond-angles are conserved. Between the two scale of order, the medium-range order in a few 10 nm scale is important. For example, photo-induced crystallization of amorphous materials does not occur immediately at the irradiation, but it proceed after some ratent period under the irradiation. Perhaps some ordering states are developed during the ratent period, and there are large fluctuations in the amorphous states. The aim of this research is to clarify local character of amorhous semiconductors, such as the medium-range fluctuations, and fractal structures in the photo-induced crystallization process. In this year experimental setup has been made, and the measurement has been done preliminarly. As the result, it is difficult to observe amorphous fluctuations by Leyrey-scattering using micro-optics. One reason may be that the relating electronic state is spread wider than spacial range of fluctuations. We have rearranged the optical system for Raman scattering measurement with a liquid He cryostat to study the network vibrations in the amorphous states at low temperatures.

非晶态半导体缺乏长程有序，而键长和键角等短程有序是守恒的。在这两个有序尺度之间，10 nm尺度内的中程有序是重要的。例如，非晶态材料的光致晶化不是在照射时立即发生，而是在照射一段时间后继续进行。可能在速率过程中发展了一些有序态，非晶态有很大的涨落。本研究的目的是阐明非晶态半导体在光诱导结晶过程中的局域特征，如中程涨落和分形结构。今年已经建立了实验装置，并进行了初步的测量。因此，利用微光学的Leyrey散射很难观察到非晶态的涨落。一个原因可能是相关的电子态比空间波动范围更广。我们重新布置了测量拉曼散射的光学系统，用液体氦低温恒温器研究了低温下非晶态的网络振动。

项目成果

T.Nakaoka, Y.Wang, K.Murase, O.Matsuda, and K.Inoue: "Resonant Raman scattering in crystalline GeSe_2"Physical Review B. 61. 15569-15572 (2000)

T.Nakaoka、Y.Wang、K.Murase、O.Matsuda 和 K.Inoue：“晶体 GeSe_2 中的共振拉曼散射”物理评论 B. 61. 15569-15572 (2000)