This study uses first-principles calculations to investigate the mechanical properties and effect of strain on the electronic properties of the 2D material 1H-PbX2 (X: S, Se). Firstly, the stability of the 1H Pb-dichalcogenide structures was evaluated using Born’s criteria. The obtained results show that the 1H-PbS2 material possesses the greatest ideal strength of 3.48 N/m, with 3.68 N/m for 1H-PbSe2 in biaxial strain. In addition, 1H-PbS2 and 1H-PbSe2 are direct semiconductors at equilibrium with band gaps of 2.30 eV and 1.90 eV, respectively. The band gap was investigated and remained almost unchanged under the strain εxx but altered significantly at strains εyy and εbia. At the fracture strain in the biaxial direction (19 %), the band gap of 1H-PbS2 decreases about 60 %, and that of 1H-PbSe2 decreases about 50 %. 1H-PbS2 and 1H-PbSe2 can convert from direct to indirect semiconductor under the strain εyy. Our findings reveal that the two structures have significant potential for application in nanoelectronic devices.

Abstract
1. Introduction
2. Simulation
3. Result and Discussion
4. Conclusions
References
Author Information

• Nguyen Hoang Linh(School of Mechanical Engineering, Hanoi University of Science and Technology, Hanoi 100000, Vietnam)
• Nguyen Minh Son(School of Mechanical Engineering, Hanoi University of Science and Technology, Hanoi 100000, Vietnam)
• Tran The Quang(Department of Basic Engineering, Faculty of Technology, Thai Binh University, Thaibinh 410000, Vietnam)
• Nguyen Van Hoi(Department of Mechanical System Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea)
• Vuong Thanh(School of Mechanical Engineering, Hanoi University of Science and Technology, Hanoi 100000, Vietnam)
• Do Van Truong(School of Mechanical Engineering, Hanoi University of Science and Technology, International Research Center for Computational Materials Science, Hanoi University of Science and Technology, Hanoi 100000, Vietnam) Corresponding author