Quantum-Confined Stark Effect in Ensemble of Colloidal Semiconductor Quantum Dots  

作　　者：王志兵 张辉朝 张家雨 Huaipeng Su Y. Andrew Wang 

机构地区：[1]Department of Electronic Engineering, Southeast University, Nanjing 210096 [2]Ocean Nanotech, LLC, Springdale AR 72764, USA

出　　处：《Chinese Physics Letters》2010年第12期192-195,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No 10774023.

摘　　要：The presence of a strong, changing, randomly-oriented, local electric field, which is induced by the photo-ionization that occurs universally in colloidal semiconductor quantum dots （QDs）, makes it difficult to observe the quantum-confined Stark effect in ensemble of colloidal QDs. We propose a way to inhibit such a random electric field, and a clear quantum-confined Stark shift is observed directly in close-packed colloidal QDs. Besides the applications in optical switches and modulators, our experimental results indicate how the oscillator strengths of the optical transitions axe changed under external electric fields.The presence of a strong, changing, randomly-oriented, local electric field, which is induced by the photo-ionization that occurs universally in colloidal semiconductor quantum dots （QDs）, makes it difficult to observe the quantum-confined Stark effect in ensemble of colloidal QDs. We propose a way to inhibit such a random electric field, and a clear quantum-confined Stark shift is observed directly in close-packed colloidal QDs. Besides the applications in optical switches and modulators, our experimental results indicate how the oscillator strengths of the optical transitions axe changed under external electric fields.

关 键 词：Soft matter  liquids and polymers Condensed matter: electrical  magnetic and optical Nanoscale science and low-D systems Chemical physics and physical chemistry 

分 类 号：O471.1[理学—半导体物理] O413.1[理学—物理]