Interaction between Quantum-Confined Excitons and Lattice in Semiconductor Ultrafine Particles

半导体超细颗粒中量子限制激子与晶格的相互作用

基本信息

批准号：
03452028
负责人：
ITOH Tadashi
金额：
$ 4.54万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

In semiconductor ultrafine particles, it is important to look for various size-dependent and surface-sensitive phenomena in order to understand the quantum size effects on the electronic states, lattice vibrations and the mutual interactions. In this research project, we have investigated the optical properties of CuCl quantum dots, in which the exciton translational motion is mainly confined. The following results have been obtained concerning the exciton-lattice interactions in the restricted geometries. 1. Size-dependence of the exciton-lattice interaction has been obtained by monitoring the size- and temperature-dependent homogeneous linewidth of the confined exciton luminescence. The interaction between exciton and acoustic vibration increases with the decrease of the dot size due to the short-range character of the deformation-type interaction. 2. Photofatigue effect which appears as the reduction of the exciton luminescence intensity with the long-term exposure to the laser ligh … More t. The origin of this effect is concluded to be due to the formation of the exciton trapping center as a result of lattice relaxation on the surface. 3. Relation between high density exciton effects and excitonic optical nonlinearities has been invest igated through the observation of the nonlinear changes of excion absorption and luminescence. The optical nonlinearities are mainly caused by the mutual interaction between confined excitons, which increases with increase of the dot radius at least up to 5nm. 4. Matrix effect has been studied through the comparison of the optical properties of quantum-confined excitons in CuCl quantum dots embedded in NaCl matrix with those in borosilicate glass matrix.From the above results, the exciton-lattice interaction is concluded to play important roles in the optical properties of CuCl quantum dots. With the aid of the present results, we can expect to understand more about the new properties of semiconductor quantum dots and their dense aggregation. Less

在半导体超细颗粒中，重要的是要寻找各种尺寸依赖性和表面敏感现象，以了解对电子状态，晶格振动和相互作用的量子大小影响。在该研究项目中，我们研究了CUCL量子点的光学特性，其中令人兴奋的翻译运动主要被限制。关于受限几何形状中令人兴奋的晶格相互作用的结果已得到以下结果。 1。通过监测受刺激性刺激性亮度的尺寸和温度依赖性均匀的线宽，可以获得令人兴奋的晶格相互作用的尺寸依赖性。由于变形型相互作用的短距离特征，刺激和声学振动之间的相互作用随点大小的减小而增加。 2。光静脉效应，它看起来像是降低了令人兴奋的发光强度，长期暴露于激光液……更多t。这种效果的起源得出的是由于表面上的晶格松弛而形成了令人兴奋的诱捕中心。 3。高密度令人兴奋的效果与令人兴奋的光学非线性之间的关系是通过观察到特殊苦难和发光的非线性变化而投入的。光学非线性主要是由限制激子之间的相互作用引起的，该激子之间的相互作用至少随着DOT半径的增加而增加。 4。通过比较嵌入NaCl矩阵中的CUCL量子点中的量子限制激子的光学性能与硼硅酸盐玻璃基质中的量子量子点的光学性质进行了研究。从上述结果，令人兴奋的效果相互作用可以在cucl量子量的光学特性中扮演重要角色。借助当前结果，我们可以期望更多地了解半导体量子点的新特性及其致密聚集。较少的