Zn掺杂对量子点Cd_6Se_6及其配合物Cd_6Se_6-(OPMe_3)_6结构和性质影响的密度泛函理论研究

DFT studies on the electronic structures and properties of Zn-doped Cd_6Se_6 and Cd_6Se_6-(OPMe_3)_6 quantum dots

采用密度泛函理论对有机配体三甲基氧膦OPMe_3吸附到掺杂量子点ZnmCdnSe_6(m+n=6)上形成吸附产物的结构和性质进行了研究。金属原子Zn和Cd与配体OPMe3中的O原子形成Zn-O和Cd-O配位键,其吸附能、电荷分布、HOMO、LUMO和电子吸收光谱等性质随着掺杂Zn原子的增多而逐渐变化。研究表明向Cd6Se6中掺杂Zn原子使其电子吸收光谱出现蓝移,随着掺杂原子的增多,蓝移现象就越明显,研究结果有助于纳米材料的设计和合成。

Understanding the structures and properties of ligand-capped nanoclusters is of interest for the design,synthesis and application of semiconductor quantum dots.P-containing ligands are often used in the preparation of CdSe nanocrystals,which is an important feature for the quantum dots.The structures and properties of OPMe 3-capped Zn m Cd n Se 6（m＋n=6）quantum dots were investigated at the TPSS/def2-TZVP level.New Zn-O and Cd-O coordination bonds are formed between the Zn atom or Cd atom and the O atom of OPMe 3.The introduction of the ligands does not change the cluster architecture,while absorption energies,electron distributions,HOMO,LUMO and electronic absorption spectra of the ligands-capped Zn m Cd n Se 6 change gradually with the number of the Zn atom increasing.A blueshift in absorption band was predicted for the clusters with the increasing Zn atoms.These new geometrical and electronic properties of Zn m Cd n Se 6（OPMe 3） 6 clusters would be helpful for the nanocrystal design and synthesis.