Carvalho Alexandra, Oberg Sven, Rayson Mark J, Briddon Patrick R
Department of Physics, 13N, University of Aveiro, 3810-193 Aveiro, Portugal.
J Nanosci Nanotechnol. 2013 Feb;13(2):1035-8. doi: 10.1166/jnn.2013.6129.
The modification of the electronic structure of silicon nanocrystals using an organic dopant, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), is investigated using first-principles calculations. It is shown that physisorbed F4-TCNQ molecules have the effect of oxidizing the nanocrystal, attracting the charge density towards the F4-TCNQ-nanocrystal interface, and decreasing the excitation energy of the system. In periodic F4-TCNQ/nanocrystal superlattices, F4-TCNQ is suggested to enhance exciton separation, and in the presence of free holes, to serve as a bridge for electron/hole transfer between adjacent nanocrystals.
利用第一性原理计算研究了使用有机掺杂剂2,3,5,6-四氟-7,7,8,8-四氰基对苯二醌二甲烷（F4-TCNQ）对硅纳米晶体电子结构的修饰。结果表明，物理吸附的F4-TCNQ分子具有氧化纳米晶体的作用，将电荷密度吸引到F4-TCNQ-纳米晶体界面，并降低系统的激发能。在周期性的F4-TCNQ/纳米晶体超晶格中，F4-TCNQ被认为可以增强激子分离，并且在存在自由空穴的情况下，作为相邻纳米晶体之间电子/空穴转移的桥梁。
