Two Dimensional β-InSe with Layer-Dependent Properties: Band Alignment, Work Function and Optical Properties

David K Sang; Huide Wang; Meng Qiu; Rui Cao; Zhinan Guo; Jinlai Zhao; Yu Li; Quanlan Xiao; Dianyuan Fan; Han Zhang

doi:10.3390/nano9010082

Two Dimensional β-InSe with Layer-Dependent Properties: Band Alignment, Work Function and Optical Properties

Nanomaterials (Basel). 2019 Jan 9;9(1):82. doi: 10.3390/nano9010082.

Authors

David K Sang^{1

2}, Huide Wang³, Meng Qiu⁴, Rui Cao⁵, Zhinan Guo⁶, Jinlai Zhao^{7

8}, Yu Li⁹, Quanlan Xiao¹⁰, Dianyuan Fan¹¹, Han Zhang¹²

Affiliations

¹ Shenzhen Key Laboratory of Two Dimensional Materials and Devices, Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. dks@szu.edu.cn.
² College of Materials Science and Engineering, Shenzhen University, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen 518060, China. dks@szu.edu.cn.
³ Shenzhen Key Laboratory of Two Dimensional Materials and Devices, Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. wanghuide@szu.edu.cn.
⁴ Shenzhen Key Laboratory of Two Dimensional Materials and Devices, Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. qiumeng@szu.edu.cn.
⁵ Shenzhen Key Laboratory of Two Dimensional Materials and Devices, Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. caorui@szu.edu.cn.
⁶ Shenzhen Key Laboratory of Two Dimensional Materials and Devices, Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. guozhinan@szu.edu.cn.
⁷ Shenzhen Key Laboratory of Two Dimensional Materials and Devices, Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. zhaojl@szu.edu.cn.
⁸ College of Materials Science and Engineering, Shenzhen University, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen 518060, China. zhaojl@szu.edu.cn.
⁹ College of Materials Science and Engineering, Shenzhen University, Shenzhen Key Laboratory of Special Functional Materials, Shenzhen 518060, China. liyu@szu.edu.cn.
¹⁰ Shenzhen Key Laboratory of Two Dimensional Materials and Devices, Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. xiaoql@szu.edu.cn.
¹¹ Shenzhen Key Laboratory of Two Dimensional Materials and Devices, Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. fandy@cae.cn.
¹² Shenzhen Key Laboratory of Two Dimensional Materials and Devices, Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. hzhang@szu.edu.cn.

Abstract

Density functional theory calculations of the layer (L)-dependent electronic band structure, work function and optical properties of β-InSe have been reported. Owing to the quantum size effects (QSEs) in β-InSe, the band structures exhibit direct-to-indirect transitions from bulk β-InSe to few-layer β-InSe. The work functions decrease monotonically from 5.22 eV (1 L) to 5.0 eV (6 L) and then remain constant at 4.99 eV for 7 L and 8 L and drop down to 4.77 eV (bulk β-InSe). For optical properties, the imaginary part of the dielectric function has a strong dependence on the thickness variation. Layer control in two-dimensional layered materials provides an effective strategy to modulate the layer-dependent properties which have potential applications in the next-generation high performance electronic and optoelectronic devices.

Keywords: Indium Selenide; Layer-dependent; density functional theory; optical properties; work function.

Abstract

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