单层Cu2SeTMD异质结的原子结构和量子物性的理论研究

昆明理工大学设计（论文）专用纸单层Cu2Se/TMD异质结的原子结构和量子物性的理论研究摘要基于第一性原理计算，本文构建了单层Cu2Se/TMD(包括H-NbSe2、T-NiTe2)异质结模型并进行模拟计算，通过研究它们顶部接触的性质，计算并分析它们的能带结构以及肖特基势垒、隧穿势垒参数，来研究金属-2DSC接触界面的电子输运特性以及这两种异质结的量子物性，以期探索合适的金属-2DSC的接触构型来实现它们之间的低接触电阻，以便在纳米电子学和光电子学领域实现更好的应用发展。主要研究内容如下：(1)通过MS构建模型和VASP优化结构，得到单层Cu2Se、H-NbSe2、T-NiT2以及两者形成的异质结的结构。而在建立异质结的模型时，我们考虑尽量减少晶格失配率，以便在不影响异质结的整体特性的情况下，实现更好的界面接触。而通过能带计算表明，单层Cu2Se为直接带隙半导体，其带隙值为0.53eV。(2)实验通过构建单层Cu2Se/TMD异质结构，得到单层Cu2Se/T-NiTe2异质结的Φ，值为0.47eV,Φ，值为0.29eV,属于肖特基接触，且肖特基类型为p型，其接触势垒为0.29eV:而单层CuSe/H-NbSe2异质结的Φn值为0.52eV,Φn值为-0.08eV,为欧姆接触。(3)由于较小隧穿势垒和肖特基势垒的更有利于载流子跃迁，而根据实验结果表明，单层Cu2Se/T-NiTe2势垒异质结界面处更小，更易进行载流子跃迁。关键词：二维半导体：过渡族金属硫化物：金属接触：肖特基势垒：隧穿势垒：第一性原理计算KMUST要层朔理7大9昆明理工大学设计（论文）专用纸Theoretical study of the atomic structure andquantum physical properties of monolayerCu2Se/TMD heterojunctionsABSTRACTBased on the first-principles calculations,this paper constructs and simulates themodels of monolayer Cu2Se/TMD (including H-NbSe2,T-NiTez)heterojunctions to studythe electron transport properties of metal-2DSC contact interfaces and the quantumproperties of these two heterojunctions by investigating the properties of their top contacts,calculating and analyzing their energy band structures as well as Schottky barrier andtunneling barrier parameters.The aim is to explore the suitable contact configurations ofmetal-2DSC to achieve low contact resistance between them for better applications innanoelectronics and optoelectronics.The main studies are as follows:(1)The structures of monolayers CuSe,H-NbSe2,T-NiTe2 and the heterojunctionsformed by both were obtained by MS constructing the models and VASP optimizing thestructures.And we try to consider reducing the lattice mismatch rate when modeling theheterojunctions in order to achieve better interfacial contacts without affecting the overallproperties of the heterojunctions.And the energy band calculation shows that themonolayer CuSe is a direct band gap semiconductor with a band gap value of 0.53 eV.(2)Experimentally,by constructing a monolayer Cu2Se/TMD heterostructure,weobtained a monolayer monolayer CuzSe/T-NiTe2 heterojunction with the d-value of0.47 eV and d-value of 0.29 eV,which is a Schottky contact and the Schottky type isp-type with a contact potential of 0.29 eV;while the monolayer Cu2Se/H-NbSe2昆明理工大学设计（论文）专用纸heterojunction with the -value of 0.52 eV and -value of-0.08 eV for ohmiccontacts(3)Since the smaller tunneling barrier and Schottky barrier are more favorable forcarrier jumping,and according to the experimental results,the monolayer CuSe/T-NiTe2barrier is smaller at the heterojunction interface and easier for carrier jumping.Keywords:two-dimensional semiconductors;Transition Metal Dichalcogenides;metalcontact;schottky barrier;tunnel barrierfirst-principles calculations;lKMUST更服州理y大