ZnSe纳米晶材料的超快吸收谱  

Ultrafast Absorption Spectra of Nanocrystal ZnSe Material

作　　者：黄仕华[1] 陆昉[2] 

机构地区：[1]浙江师范大学物理系,金华321004 [2]复旦大学物理系,上海200433

出　　处：《Journal of Semiconductors》2006年第4期717-720,共4页半导体学报（英文版）

基　　金：浙江省自然科学基金资助项目(批准号:Y404363)~~

摘　　要：通过改进的溶剂热方法,以KBH4作为还原剂,在三乙胺溶液介质中制备了ZnSe纳米晶材料.与ZnSe体材料相比,其纳米材料的稳态吸收边发生了蓝移,而且纳米颗粒的尺寸越小,蓝移量越大,这是由于随着尺度减少而引起的量子限制效应增强造成的.对在溶液中的ZnSe纳米颗粒的超快吸收谱的研究表明,当纳米颗粒的平均尺寸为75nm时,电子声子散射时间为8.74ps;当平均尺寸为45nm时,散射时间为2.77ps.随着纳米颗粒尺寸的减小,载流子与颗粒表面的非弹性碰撞几率增加,从而使载流子声子耦合的强度增强,导致载流子声子散射时间缩短.Using a modified solvothermal method in which potassium borohydride is employed as a reducing reagent, nano. crystal ZnSe materials are prepared in a triethylamine solvent. Compared to bulk ZnSe, nanocrystal ZnSe has a blue shift in its steady absorption edge. The degree of this blue shift increases with the decrease of nanocrystal particle size,as a result of quantum confinement effects. The ultrafast absorption spectra of ZnSe nanocrystals indicate that the electron-electron scattering time is 8. 74ps and 2.77ps for the average nanocrystal size of 75 and 45 nm,respectively. With the decrease of the size of nanocrystal, the probability of inelastic collision among carriers and nanocrystal surface increases, resulting in the enhancement of the carrier-phonon coupling strength and the shortening of the carrier-photon scattering time.

关 键 词：ZnSe纳米晶材料 超快吸收谱 载流子-声子散射 

分 类 号：TN304[电子电信—物理电子学]