Ultrafast optical spectroscopy of surface-modified silicon quantum dots: unraveling the underlying mechanism of the ultrabright and color-tunable photoluminescence  

作　　者：Lei Wang Qi Li Hai-Yu Wang Jing-Chun Huang Ran Zhang Qi-Dai Chen Huai-Liang Xu Wei Han Zheng-Zhong Shao Hong-Bo Sun 

机构地区：[1]State Key Laboratory on Integrated Optoelectronics,College of Electronic Science and Engineering,Jilin University,Changchun 130012,China [2]College of Physics,Jilin University,Changchun 130012,China [3]State Key Laboratory of Molecular Engineering of Polymers,Advanced Material Laboratory,Department of Macromolecular Science,Fudan University,Shanghai 200433,China

出　　处：《Light(Science & Applications)》2015年第1期524-531,共8页光（科学与应用)（英文版）

基　　金：HBS thanks the Natural Science Foundation of China(NSFC)under Grant Nos.91423102,21273096,91323301 and 11104109;the National Basic Research Program of China(973 Program)under Grant No.2014CB921302 for support.

摘　　要：In this work,the fundamental mechanism of ultrabright fluorescence from surface-modified colloidal silicon quantum dots is investigated in depth using ultrafast spectroscopy.The underlying energy band structure corresponding to such highly efficient direct bandgap-like emissions in our surface-modified silicon quantum dots is unraveled by analyzing the transient optical spectrum,which demonstrates the significant effect of surface molecular engineering.It is observed that special surface modification,which creates novel surface states,is responsible for the different emission wavelengths and the significant improvement in the photoluminescence quantum yields.Following this essential understanding,surface-modified silicon quantum dots with deep blue to orange emission are successfully prepared without changing their sizes.

关 键 词：quantum confinement silicon quantum dots surface molecular engineering ultrafast spectroscopy wave function modification 

分 类 号：R52[医药卫生—内科学]