学　术

　　由基础与前沿研究院主办的基础沙龙第37期邀请到湖南大学在读博士赵蓓作学术交流。具体安排如下，欢迎师生们参加。

　　主　题：Complex heterostructure and superlattices based on self-assembly of two-dimensional materials

　　主讲人：赵蓓（湖南大学博士生）

　　时　间：2021年3月25日（周四）9:30-10:10

　　地　点：沙河校区通信楼725室

　　主讲人简介：

　　赵蓓，湖南大学2017级在读博士。目前致力于新型二维材料和二维复杂结构（包括垂直异质结、多异质结、超晶格、异质结阵列）的制备、光电性质和先进光电功能器件的研究。2017年至今，在Nature、Nat. Electron.、Nat. Commun.、J. Am. Chem. Soc.、Adv. Mater.等知名学术期刊上发表论文20余篇。 其中，以第一作者身份、湖南大学为第一单位发表Nature1篇，J. Am. Chem. Soc. 1篇，Adv. Mater 1篇，Nano Res. 1篇，申请中国发明专利3项（已公开），其中两项已授权。

　报告摘要：

　　The van der Waals (vdW) heterostructures and vdW superlattice based on two-dimensional materials have provided great flexibility for integrating distinct atomic layers beyond the traditional limits of lattice-matching requirements，which have potential in the field of vertical tunnel transistors, new optoelectronic devices, flexible devices and integrated circuit. So far, 2D vdW heterostructures and vdW superlattices have been mostly obtained through a mechanical exfoliation and arduous layer-by-layer restacking process. This approach is generally applied to create diverse heterostructures from a wide range of layered crystals, but typically with limited yield and reproducibility, and becomes exponentially more challenging for complex heterostructure and high-order superlattices which are clearly not scalable for practical applications. Here，we present chemical vapor deposition approach to synthesis of these atomically thin materials and scalable construction of complex heterostructures and superlattices with designed spatial modulation of chemical compositions and electronic structures. The main contents as follows:（1）By controlling the growth temperature, we show that the highly uniform NiTe2single crystals can be synthesized with precisely tunable thickness varying from 1, 2, 3, ... to multilayers with a standard deviation (∼0.3 nm) of less than the thickness of a monolayer layer NiTe2and investigate the thickness dependent electronic properties.（2）we report thein situgrowth of ultrathin metallic NiSe single crystals on WSe2in which the metallic NiSe nanosheets function as the contact electrodes to WSe2, creating an interface that is essentially free from chemical disorder and improve the performance of 2D semiconductor. (3) we defines a straightforward pathway to high-order vdW superlattices with widely variable material compositions, dimensions and charities. It for the first time realizes high-order superlattices from a series of 2D materials as well as 3D or 1D components, offer a versatile artificial material platform for fundamental investigation of the emergent properties and realization of totally new device functions.