Surface and intrinsic contributions to extinction properties of ZnSe quantum dots

作     者：Shangxin Lin Jiongzhao Li Chaodan Pu Hairui Lei Meiyi Zhu Haiyan Qin Xiaogang Peng Shangxin Lin;Jiongzhao Li;Chaodan Pu;Hairui Lei;Meiyi Zhu;Haiyan Qin;Xiaogang Peng

作者机构：College of Information Science and TechnologyHuaqiao UniversityXiamen361021China Center for Chemistry of Novel&High-Performance MaterialsDepartment of ChemistryZhejiang UniversityHangzhou310027China 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2020年第13卷第3期

页      面：824-831页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：This work was funded by the National Key Research and Development Program of China(No.2016YFB0401600) the National Natural Science Foundation of China(No.91833303) Joint NSFC-ISF Research(No.21761142009) the education department of Fujian Province(No.JA13013) 

主　　题：quantum dots ZnSe extinction coefficient surface state 

摘      要：This work studies extinction properties of ZnSe quantum dots terminated with either Se-surface or Zn-surface(Se-ZnSe or Zn-ZnSe QDs).In addition to commonly observed photoluminescence quenching by anionic surface sites,Se-ZnSe QDs are found to show drastic signatures of Se-surface states in their UV-visible(Vis)absorption *** to most QDs reported in literature,monodisperse Zn-ZnSe QDs show sharp absorption features and blue-shifted yet steep absorption edge respect to the bulk ***,for monodisperse Se-ZnSe QDs,all absorption features are smeared and a low-energy tail is identified to extend to an energy window below the bulk ZnSe *** increasing their size,a cyclic growth of ZnSe QDs switches their surface from Zn-terminated to Se-terminated ones,which confirms that the specific absorption signatures are reproducibly repeated between those of two types of the *** the extinction coefficients per unit of Se-ZnSe QDs are always larger than those of Zn-ZnSe QDs with the same size,both of them approach the same bulk *** addition to contribution of the lattice,extinction coefficients per nanocrystal of Zn-ZnSe QDs show an exponential term against their sizes,which is expected for quantum-confinement enhancement of electron-hole wavefunction *** Se-ZnSe QDs,there is the third term identified for their extinction coefficients per nanocrystal,which is proportional to the square of size of the QDs and consistent with surface contribution.