Prediction of new phase 2D C-2h group III monochalcogenides with direct bandgaps and highly anisotropic carrier mobilities

Hu, Tuo1,2,3; Xu, Congsheng1,2; Zhang, Ao4; Yu, Peiyuan1,2

2022

10.1039/d1ma01068a

MATERIALS ADVANCES   影响因子和分区

2633-5409

Two-dimensional (2D) group III monochalcogenides (MX, M = Ga, In and X = S, Se, Te) are promising candidates for next-generation ultrathin optoelectronic devices due to their exotic properties. However, the lack of direct band gaps and the low hole mobilities in their conventional single-layer D-3h phase hinder their potential utility for various applications. In this work, new polymorphs of 2D MXs belonging to the space group C-2h are predicted through a global structural search based on artificial swarm intelligence and density functional theory calculations. We demonstrate that such monolayer polymorphs are thermodynamically and kinetically stable through phonon spectrum analysis and ab initio molecular dynamics simulations. Direct band gaps of 2.38 to 2.84 eV are revealed in all C-2h MX monolayers, a property that traditional 2D D-3h MXs do not possess. Calculations based on the Boltzmann Transport Equation method show that electron mobilities in C-2h monolayers are significantly higher in magnitude than those of the conventional D-3h phase. Anisotropic optical properties are predicted and high absorption coefficients covering the UV-visible spectra are also reported. All these features render the new C-2h MX monolayers promising candidates for potential applications in high-efficiency solar cells and anisotropic optoelectronic devices.

ESCI

英语

第一 ; 通讯

SUSTech startup fund[Y01216143] ; Guangdong Basic and Applied Basic Research Foundation[2021A1515010387]

Materials Science

Materials Science, Multidisciplinary

WOS:000749716300001

ROYAL SOC CHEMISTRY

Web of Science

1.Southern Univ Sci & Technol, Dept Chem, Shenzhen 518055, Peoples R China
2.Southern Univ Sci & Technol, Shenzhen Grubbs Inst, Shenzhen 518055, Peoples R China
3.Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA
4.Southern Univ Sci & Technol, Dept Phys, Shenzhen 518055, Peoples R China

Hu, Tuo,Xu, Congsheng,Zhang, Ao,et al. Prediction of new phase 2D C-2h group III monochalcogenides with direct bandgaps and highly anisotropic carrier mobilities[J]. MATERIALS ADVANCES,2022.

Hu, Tuo,Xu, Congsheng,Zhang, Ao,&Yu, Peiyuan.(2022).Prediction of new phase 2D C-2h group III monochalcogenides with direct bandgaps and highly anisotropic carrier mobilities.MATERIALS ADVANCES.

Hu, Tuo,et al."Prediction of new phase 2D C-2h group III monochalcogenides with direct bandgaps and highly anisotropic carrier mobilities".MATERIALS ADVANCES (2022).