氢化非晶硅薄膜类TO模的喇曼特征  

RAMAN SCATTERING FEATURES OF TO-LIKE MODE IN HYDROGENATED AMORPHOUS SILICON THIN FILMS

作　　者：程光煦[1] 陈坤基[1] 夏桦[1] 张维[1] 张杏奎[1] 

机构地区：[1]南京大学现代分析中心,南京大学固体微结构物理国家实验室

出　　处：《南京大学学报（自然科学版）》1994年第3期444-450,共7页Journal of Nanjing University（Natural Science）

摘　　要：文中给出了不同制备衬底温度（Ｔｓ）氢化非晶硅薄膜的喇曼谱，对类ＴＯ模（Ｔ—ｌｉｋｅｍｏｄｅ）的喇曼峰位形变化特征及与之相应的物理结果给出了较详细的讨论：惯用描述Ｓｉ－Ｓｉ原子间互作用的莫尔斯（Ｍｏｒｓｅ）势，在α─Ｓｉ：Ｈ结构中已不再适用，需由Ｔｅｒｏｓｆｆ势取代．此外，还简述了出现ＬＯ，ＬＡ振动模式的可能结构及其物理机制．最后，给出了新结构序参量Ｃ（非谐性势Ｖ（ｒ）ｎ＝０，１，２，…中四次方项系数与三次方项系数之比）与结构间的关联．这些都进一步地揭示了氢化非晶硅膜结构的特征．Raman spectra of hydrogenated amorphous silicon grown under different substrate temperatures are presented. It has been welll recogized that the bond angle flucturation in hydrogenated amorphous silicon results in line broadening of the TO phonon branch and that the shift of the peak position can be interpreted by means of the a-Si:H structural changes.The experimental results show that Morse potential is not valid.To describe the interaction between St and St atoms,and it away be replaced by Tersoff potential. This paper contains an experimental and inferential reason for this conclosion.New order parameter, C =△ωto/Γ2, which is the ratio of the coefficients of the quartic to cubic terms of the potential, i.e. V(r) n = 0, 1, 2, 3, 4, ...C= A4 / A3, can be obtained from the position shift of TO-like mode conveniently, the Physical principle of C are already derived from a few equations. Finally, the multi-number rings structures on a-Si:H for 250℃ substrate temperature details are discussed, especial,the LA and LO vibratory modes are done, some coupling mechanism between light electric magnetic field and LA or LO modes are given, too.

关 键 词：氢化非晶硅 类TO模 薄膜 散射谱 

分 类 号：O484.4[理学—固体物理]