权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Growth of Urtra-thin Films and Their Nonlinear Optical Response in Layered Semiconductors

层状半导体中超薄膜的生长及其非线性光学响应

基本信息

批准号：
08454084
负责人：
KOMATSU Teruo
金额：
$ 5.06万
依托单位：
Osaka City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08454084/
关键词：
Hot-wall method urtra thin films BiI_3 Van der waals epitaxtial growth linear optical response nonlinear optical response high density excitions 非線形光学応答 BiI_3 ファンデアリールスエピタキシャル成長層状半導体ホットウォール法エピタキシャル成長励起子遷移量子サイズ効果

项目摘要

We'v prepared very thin micro-crystals of BiI_3 on the creaved substrate of CdI_2 single crystals and on the (1ll) creaved surface of CaF_2 single crystals by using a Hotwall method. The microcrystallites having a disk-like shape with mono-layer thickness were grown in CdI_2 matrices. In these crystals we have studied structural characteristics by using a transmission electron microscope and AFM technique in connection with optical properties and behavior of the excitons at high density.The exciton absorption band with narrow line width similar in bulk crystals was observed in the samples with the thickness of 300 A of BiI_3 grown on the substrate of creaved CdI_2 crystals. New absorption band appeared and resonant luminescence band at 2.02eV was observed in the case of the sample with very small evaporation rate of BiI_3 on the (111) creaved surface of CaF_2 single crystals by using a Hotwall method.For the resonant excitation at the microcrystallite bands in CdI_2 matrices, luminescence bands appear with Stokes shifts. A quantum disk model in which the center of mass motion of the exciton is confined and a theory of the size-dependent exciton-acoustic phonon interaction in the quantum disks have been developed. Nonlinear optical rsponse of the excitons in such microcrystallites with thin layer thickness have been investigated. From the analysis of the excitation energy dependence of the luminescence spectra, stability of the biexciton states in microcrystaliites was discussed.

我们用热壁法在CdI_2单晶的开槽衬底和CaF_2单晶的（111）开槽表面上制备了很薄的BiI_3微晶。在CdI_2基质中生长出单层厚度的盘状微晶。用透射电子显微镜和原子力显微镜（AFM）研究了这些晶体的结构特征、光学性质和高密度激子的行为，发现在CdI_2晶体衬底上生长的300厚BiI_3样品中，出现了与块体晶体相似的窄线宽激子吸收带。用热壁法研究了BiI_3蒸发速率很小的样品在CaF_2单晶（111）面上产生的吸收带和2.02eV的共振发光带，以及CdI_2基体中微晶带的共振激发产生的Stokes位移发光带。本文提出了一个限制激子质心运动的量子盘模型和量子盘中激子-声学声子相互作用的尺寸依赖理论。研究了这种薄层微晶中激子的非线性光学响应。通过对荧光光谱的激发能依赖性的分析，讨论了微晶中双激子态的稳定性。