Issue 31, 2024

Bi3O2.5Se2: a two-dimensional high-mobility polar semiconductor with large interlayer and interfacial charge transfer

Abstract

Two-dimensional semiconductors with large intrinsic polarity are highly attractive for applications in high-speed electronics, ultrafast and highly sensitive photodetectors and photocatalysis. However, previous studies mainly focus on neutral layered polar 2D materials with limited vertical dipoles and electrostatic potential difference (typically <1.5 eV). Here, using the first-principles calculations, we systematically investigated the polarity of few-layer Bi3O2.5Se2 semiconductors with ultrahigh predicted room-temperature carrier mobility (1790 cm2 V−1 s−1 for the monolayer). Thanks to its unique non-neutral layered structure, few-layer Bi3O2.5Se2 contributes to a substantial interlayer charge transfer (>0.5 e) and almost the highest electrostatic potential difference (ΔΦ) of ∼4 eV among the experimentally attainable 2D layered materials. More importantly, positioning graphene on different charged layers ([Bi2O2.5]+ or [BiSe2]) switches the charge transfer direction, inducing selective n-doping or p-doping. Furthermore, we can use polar Bi3O2.5Se2 as an exemplary assisted gate to gain additional holes or electrons except for the external electric field, thus breaking the traditional limitations of gate tunability (∼1014 cm−2) observed in experimental settings. Our work not only expands the family of polar 2D semiconductors, but also makes a conceptual advance on using them as an assisted gate in transistors.

Graphical abstract: Bi3O2.5Se2: a two-dimensional high-mobility polar semiconductor with large interlayer and interfacial charge transfer

Supplementary files

Article information

Article type
Paper
Submitted
22 Apr 2024
Accepted
23 Jun 2024
First published
25 Jun 2024

Nanoscale, 2024,16, 14766-14774

Bi3O2.5Se2: a two-dimensional high-mobility polar semiconductor with large interlayer and interfacial charge transfer

X. Dong, Y. Hou, C. Deng, J. Wu and H. Fu, Nanoscale, 2024, 16, 14766 DOI: 10.1039/D4NR01758G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements