Article
Chemistry, Physical
Xing Chen, Yaqi Liu, Weicheng Gao, Guang Yang, Ali Hamza Qureshi, Ming Chen, Xiaojing Yao, Min Zhou, Xiuyun Zhang, Yongjun Liu
Summary: Research shows that defective two-dimensional transition metal dichalcogenides/graphene heterostructures exhibit better hydrogen evolution catalytic activity than pure MX2/Gs and freestanding MX2 monolayers in water electrolysis. In particular, MX2/G_V(X)s with S(Se) vacancies show catalytic performance comparable to that of Pt.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Lihong Han, Qian Zhang, Xiaoning Guan, Baonan Jia, Chao Dong, Weixia Zou, Shuli Gao, Haizhi Song, Pengfei Lu
Summary: This paper investigates the interface between monolayer transition metal dichalcogenides (TMDs) and SiO2 using a first-principles method. It is found that the Si-terminal forms van der Waals interaction with large interlayer spacing, making it a candidate material. The band gap of the interface decreases as the atomic radius of metal atoms increases. The MoS2/SiO2(M3) configuration has the highest potential difference. The MX2 materials cause a redshift in the optical absorption of SiO2, and the structure with Mo atoms enhances the optical absorption intensity of SiO2 more effectively. The composite of new materials greatly enhances the optical absorption, providing a theoretical basis for the design of new optoelectronic devices.
SURFACES AND INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Seyedeh Alieh Kazemi, Sadegh Imani Yengejeh, Samuel Akinlolu Ogunkunle, Lei Zhang, William Wen, Alan Wee-Chung Liew, Yun Wang
Summary: Monolayers of transition metal dichalcogenides (TMD) have excellent mechanical and electrical characteristics. This study investigates the effects of vacancies on the electrical and mechanical properties of TMDs through first-principles density functional theory (DFT). The results show that anion vacancy defects have a slight impact on the properties, while vacancies in metal complexes significantly affect the electronic and mechanical properties. The study also reveals that the mechanical properties of TMDs are influenced by their structural phases and anions.
Article
Chemistry, Physical
H. U. Din, M. Idrees, Q. Alam, B. Amin
Summary: This study investigates the structural, optical, and photocatalytic properties of van der Waals heterostructures of transition metal dichalcogenides MX2 and boron pnictides BY using hybrid density functional calculations. The results demonstrate excellent charge transfer and optical absorption characteristics in BY-MX2 heterostructures, making them promising for light harvesting applications and photocatalytic water splitting.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
H. Khan, M. U. Ashraf, M. Idrees, H. U. Din, Chuong Nguyen, B. Amin
Summary: Using first principles calculations, this study investigates the electronic band structure and Schottky contact properties of CS-MX2 and CS-MXY MS vdWH. The results show that the electronic band structures of CS-MX2 and CS-MXY MS vdWH can be considered as a simple sum of CS, MX2, and MXY monolayers, with the electronic properties of these layers well-preserved in the vdWH. Furthermore, CS-WS2 and CS-MoSeTe exhibit smaller effective mass and therefore hold promising prospects for nanoelectronic and optoelectronic devices.
Article
Thermodynamics
Wenlong Bao, Guofu Chen, Zhaoliang Wang, Dawei Tang
Summary: This study investigates the thermal properties and thermal transport mechanism of monolayer and bilayer MoS2 and WS2, as well as MoS2/WS2 heterostructure. The results show that the thermal conductivity of bilayer systems is higher, while the thermal conductivity of MoS2/WS2 heterostructure is lower. Phonon dispersion, scattering rate, and Gruneisen parameters are important factors for understanding the thermal transport mechanism. Interlayer charge transfer and interlayer coupling play a significant role in the thermal transport of MoS2/WS2 heterostructure.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Chemistry, Physical
Tahir Wahab, Yun Wang, Antonio Cammarata
Summary: In this study, the structural, opto-electronic, and photocatalytic properties of GeC-MX2 (M = Mo, W, X = S, Se) van der Waals heterostructures for photocatalysis were systematically investigated using first-principles computations. The results showed that the GeC-MX2 heterostructures could absorb visible light and allow for continuous separation of photogenerated electron-hole pairs. The induced electric field at the interface between the GeC and MX2 monolayers was essential for preventing the recombination of photogenerated charges. Additionally, the band-edge locations suggested that GeC-MX2 heterostructures could be utilized as a photocatalyst for water splitting. Overall, the opto-electronic properties of these novel GeC-MX2 heterostructures made them suitable for future photocatalysis applications.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Aman Kassaye Sibhatu, Tamiru Teshome, Omololu Akin-Ojo, Abubeker Yimam, Georgies Alene Asres
Summary: The van der Waals heterostructure of Janus materials with a TMD monolayer is a potential method for enhancing the performance of photovoltaic systems. The MX2/ZrXO van der Waals heterostructures demonstrate favorable stacking, stability, and excellent photovoltaic properties with a maximum achieved power conversion efficiency of above 22%. The heterostructure materials also exhibit high absorption efficiency, making them ideal for photovoltaic solar cell applications.
Article
Materials Science, Multidisciplinary
Dongxue Zhang, Baozeng Zhou
Summary: Using density functional theory calculations, the spin direction in nonmagnetic BX/MX2 van der Waals heterostructures can be controlled and stabilized. The electronic structures of the heterostructures exhibit different band alignments, and the dominant carrier spin direction around the valence-band edge can be effectively tuned by applying biaxial strain and external electric field.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Nanoscience & Nanotechnology
Yi Peng, Qianqian Zhu, Wangping Xu, Juexian Cao
Summary: This study synthesized a new two-dimensional monolayer W8Se12 structure via in situ electron-beam irradiation and systematically studied the photoelectric properties of monolayer M8X12 materials. The results showed that W8Se12 monolayer has a desirable direct band gap and anisotropic optical absorption, and can undergo a direct-indirect-metal transition under strain.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Alaa Akkoush, Yair Litman, Mariana Rossi
Summary: In this study, the structural and electronic characteristics of point defects in monolayer transition metal dichalcogenides MX2 were investigated using density functional theory. The stability and electronic structure of charged vacancy defects in monolayer MoS2 were found to be influenced by temperature and external conditions. A charge compensation scheme based on the virtual crystal approximation was employed for the simulation of charged defects. The study also provided experimental evidence that the vacancy defect is negatively charged.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Physics, Multidisciplinary
Zhi-Hai Sun, Jia-Xi Liu, Ying Zhang, Zi-Yuan Li, Le-Yu Peng, Peng-Ru Huang, Yong-Jin Zou, Fen Xu, Li-Xian Sun
Summary: In this work, the influences of interfacial defects on the electronic structures and photocatalytic properties of hBN/MX (2) heterostructures are studied using density functional theory calculations. The results reveal that the band alignment of the heterostructures can be adjusted by introducing vacancies and atomic doping. The interfacial defects can be used to engineer the photocatalysis properties.
Article
Optics
Gonghe Du, Qianwen Yang, Xudong Hu, Shuangxiong Ma, Yani Ren, Yonggang Xu, Zhaoyu Ren, Qiyi Zhao, Lu Li
Summary: The electrostatic potential and optoelectronic characteristics of Janus MoSSe/MX2 (M = Mo, X = S, Se) van der Waals (vdW) heterostructures were studied using strain engineering. Uniaxial strain not only induced direct and indirect band gaps and semiconductor-metal transformation, but also enhanced the electric field at the interface and improved optical adsorption properties in the IR-visible range. This study reveals the photophysical properties of MoSSe/MX2 vdW heterostructures and highlights their potential for optoelectronic devices and photocatalysis applications.
JOURNAL OF NONLINEAR OPTICAL PHYSICS & MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Anjna Devi, Arun Kumar, P. K. Ahluwalia, Amarjeet Singh
Summary: The study systematically elucidates the tunable spin-resolved electronic and optical properties of MX2 materials, highlighting their magnetic and semiconductor characteristics and potential applications in spintronics and photovoltaic devices.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Luiz Claudio de Carvalho, Rodrigo Santos da Lapa, Simone Silva Alexandre, Ricardo Wagner Nunes
Summary: In this study, the structural and thermodynamic properties of 2D transition-metal dichalcogenides alloys Mo(1-x)W x (S, Se, Te)(2) were investigated using ab initio calculations. The results show that the alloy composition has a weak influence on the structural properties, while the chalcogen species have a stronger influence. The electronic band gaps of the alloys exhibit a small but significant bowing as a function of composition. The thermodynamic properties indicate that the alloys are in a fully mixed state without any phase separation.