摘要
异质结构的构筑与堆垛是新型二维材料物性调控及应用的有效策略.基于密度泛函理论的第一性原理计算,本文研究了4种不同堆叠构型的新型二维Janus Ga_(2)SeTe/In_(2)Se_(3)范德瓦耳斯异质结的电子结构和光学性质.4种异质结构型均为Ⅱ型能带结构的间接带隙半导体,光致电子的供体和受体材料由二维In_(2)Se_(3)的极化方向决定.光吸收度在可见光区域高达25%,有利于太阳可见光的有效利用.双轴应变可诱导直接-间接带隙转变,外加电场能有效调控异质结构带隙,使AA2叠加构型的带隙从0.195 eV单调增大到0.714 eV,AB2叠加构型的带隙从0.859 eV单调减小到0.058 eV,两种调控作用下异质结的能带始终保持Ⅱ型结构.压缩应变作用下的异质结在波长较短的可见光区域表现出更优异的光吸收能力.这些研究结果揭示了Janus Ga_(2)SeTe/In_(2)Se_(3)范德瓦耳斯异质结电子结构的调控机理,为新型光电器件的设计提供理论指导.
Stacking two-dimensional materials into heterogeneous structures is an effective strategy to regulate their physical properties and enrich their applications in modern nanoelectronics.The electronic structure and optical properties of a new two-dimensional Janus Ga_(2)SeTe/In_(2)Se_(3)heterojunction with four stacked configurations are investigated by first principles calculations.The heterojunction of the four configurations is an indirect band-gap semiconductor with a type-Ⅱ band structure,and the photoelectron donor and acceptor materials are determined by the polarization direction of two-dimensional In_(2)Se_(3).The light absorption rises to 25%in the visible region,which is conducive to the effective utilization of the solar visible light.The biaxial strain can induce direct-indirect bandgap transition,and the applied electric field can effectively regulate the bandgap of heterogeneous structure.The bandgap of AA2 configuration increases monotonically from 0.195 eV to 0.714 eV,but that of AB2 configuration decreases monotonically from 0.859 eV to 0.058 eV.The band of the heterojunction always maintains the type-Ⅱ structure under the two kinds of configurations.The heterojunctions under compressive strain show better light absorption capability in the visible region with shorter wavelength.These results reveal the regulatory mechanism of the Janus Ga_(2)SeTe/In_(2)Se_(3)van der Waals heterojunction electronic structure and provide theoretical guidance in designing novel optoelectronic devices.
作者
孙婷钰
吴量
何贤娟
姜楠
周文哲
欧阳方平
Sun Ting-Yu;Wu Liang;He Xian-Juan;Jiang Nan;Zhou Wen-Zhe;Ouyang Fang-Ping(School of Physics and Electronics,Hunan Key Laboratory for Super-Microstructure and Ultrafast Process,Hunan Key Laboratory of Nanophotonics and Devices,Central South University,Changsha 410083,China;School of Physics and Technology,State Key Laboratory Of Chemistry And Utilization Of Carbon Based Energy Resources,Xinjiang University,Urumqi 830046,China;State Key Laboratory of Powder Metallurgy,and Powder Metallurgy Research Institute,Central South University,Changsha 410083,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第7期328-338,共11页
Acta Physica Sinica
基金
国家自然科学基金(批准号:52073308,12164046)
湖南省杰出青年学者基金(批准号:2015JJ1020)
新疆维吾尔自治区天池特聘教授基金资助的课题.
关键词
Janus单层
范德瓦耳斯异质结
光电特性
第一性原理
Janus single layer
Van der Waals heterojunction
photoelectric characteristics
first principles
