CdS_(0.1)Se_(0.9)纳米晶体的电光性质  

Electro-optical Properties of CdS_(0.1)Se_(0.9) Nanocrystals

作　　者：孙萍[1] 王引书[1] 王若桢[1] 林永昌[2] 

机构地区：[1]北京师范大学物理系,北京100088 [2]北京理工大学光电工程系,北京100081

出　　处：《量子电子学报》2002年第1期70-73,共4页Chinese Journal of Quantum Electronics

基　　金：国家自然科学基金资助项目(29890217)

摘　　要：对嵌埋于玻璃基体中的ＣｄＳ０．１Ｓｃ０．９纳米晶体进行了室温电调制透射谱测量，观察到较强的共振和非共振电光响应倚号（１０－４～１０－３）．共振电光响应具有如下特征：同一组分的纳米晶体其倩号的峰位随着尺寸减小向高能方向移动；同一样品谱线形状不随外电场强度而变；信号幅度与外电场强度的平方成线性关系，并且随调制频率的增加而减小；共振电光效应的物理机制是量子受限的Ｓｔａｒｋ效应．非共振电光响应信号呈与波长有关的振荡线形；外电场强度增加，非共振电光响应信号幅度也增加；用介电受限的局域场增强理论解释了非共振电光效应的物理机制．Electromodulation transmittance spectroscopy of CdS0.1Se0.9 nanocrystals embeded in the glass matrix is measured at room-temperature. Stronger electro-optical signals (10-4 - 10-3) are observed in both resonant and nonresonant regimes. These are some experimental results in resonant regime. The peak positions of electro-optical signals shift to higher energy direction when the nanocrystal size decreases; the line-shape of spectra for the same sample is independent of the external electric field strength; there are linear relationship between the signal magnitudes scale and the square of applied field strength, which indicates that the electro-optical effect of nanocrystals is the Kerr effect and the nanocrystals have the third-order nonlinear optical sus- ceptibility X(3); the signal magnitudes decrease when the modulation frequencies increase. The physical mechanism of resonant electro-optical effect is consistent with quantum-confined Stark effect. The oscillatory electro-optical signals in nonresonant regime are observed at frequency of 230 Hz. The magnitudes of nonresonant electro-optical signal tend to enhance with the in- creasing of the external electric field strength. The origin of nonresonant electro-optical effect is described with' dielectric confinement' effect.

关 键 词：电调制透射谱 纳米晶体 电光效应 电光性质 

分 类 号：O734.1[理学—晶体学]