School of Physics, Southeast University, Nanjing, 211189, P.R. China.
Synergetic Innovation Center for Quantum Effects and Applications (SICQEA), Hunan Normal University, Changsha, 410081, China.
Angew Chem Int Ed Engl. 2017 Aug 21;56(35):10501-10505. doi: 10.1002/anie.201706038. Epub 2017 Jul 24.
Sulfur vacancies (SVs) inherent in MoS are generally detrimental for carrier mobility and optical properties. Thiol chemistry has been explored for SV repair and surface functionalization. However, the resultant products and reaction mechanisms are still controversial. Herein, a comprehensive understanding on the reactions is provided by tracking potential energy surfaces and kinetic studies. The reactions are dominated by two competitive mechanisms that lead to either functionalization products or repair SVs, and the polarization effect from decorating thiol molecules and thermal effect are two determining factors. Electron-donating groups are conducive to the repairing reaction whereas electron-withdrawing groups facilitate the functionalization process. Moreover, the predominant reaction mechanism can be switched by increasing the temperature. This study fosters a way of precisely tailoring the electronic and optical properties of MoS by means of thiol chemistry approaches.
硫空位（SVs）在 MoS 中普遍不利于载流子迁移率和光学性质。硫醇化学已被探索用于 SV 修复和表面功能化。然而，所得产物和反应机制仍存在争议。在此，通过跟踪势能面和动力学研究，提供了对反应的全面理解。反应主要由两种竞争性机制主导，导致功能化产物或修复 SVs，并且修饰硫醇分子的极化效应和热效应是两个决定因素。供电子基团有利于修复反应，而吸电子基团有利于功能化过程。此外，通过提高温度可以切换主要反应机制。这项研究通过硫醇化学方法为精确调整 MoS 的电子和光学性质提供了一种方法。
