Title: Robust Large Gap Two-Dimensional Topological Insulators in Hydrogenated III–V Buckled Honeycombs

Abstract

A large gap two-dimensional (2D) topological insulator (TI), also known as a quantum spin Hall (QSH) insulator, is highly desirable for low-power-consuming electronic devices owing to its spin-polarized backscattering-free edge conducting channels. Although many freestanding films have been predicted to harbor the QSH phase, band topology of a film can be modified substantially when it is placed or grown on a substrate, making the materials realization of a 2D TI challenging. In this work we report a first-principles study of possible QSH phases in 75 binary combinations of group III (B, Al, Ga, In, and Tl) and group V (N, P, As, Sb, and Bi) elements in the 2D buckled honeycomb structure, including hydrogenation on one or both sides of the films to simulate substrate effects. A total of six compounds (GaBi, InBi, TlBi, TlAs, TlSb, and TlN) are identified to be nontrivial in unhydrogenated case; whereas for hydrogenated case, only four (GaBi, InBi, TlBi, and TlSb) remains nontrivial. The band gap is found to be as large as 855 meV for the hydrogenated TlBi film, making this class of III–V materials suitable for room temperature applications. TlBi remains topologically nontrivial with a large band gap at various hydrogen coverages,more » suggesting the robustness of its band topology against bonding effects of substrates.« less

Authors:

Crisostomo, Christian P. ^[1]; Yao, Liang-Zi ^[1]; Huang, Zhi-Quan ^[1]; Hsu, Chia-Hsiu ^[1]; Chuang, Feng-Chuan ^[1]; Lin, Hsin ^[2]; Albao, Marvin A. ^[3]; Bansil, Arun ^[4]

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+ Show Author Affiliations

1. National Sun Yat-sen Univ. (Taiwan)
2. National Univ. of Singapore (Singapore)
3. Univ. of The Philippines Los Baños, Laguna, (Philippines)
4. Northeastern Univ., Boston, MA (United States)

Publication Date:

Mon Sep 21 00:00:00 EDT 2015

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Center for the Computational Design of Functional Layered Materials (CCDM)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1371091

Grant/Contract Number:  

SC0012575; FG02-07ER46352; AC02-05CH11231

Resource Type:

Journal Article: Accepted Manuscript

Journal Name:

Nano Letters

Additional Journal Information:

Journal Volume: 15; Journal Issue: 10; Related Information: CCDM partners with Temple University (lead); Brookhaven National Laboratory; Drexel University; Duke University; North Carolina State University; Northeastern University; Princeton University; Rice University; University of Pennsylvania; Journal ID: ISSN 1530-6984

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 2D topological insulators; topological phase transition; quantum spin Hall effect; III−V semiconductor thin films; electronic structures; first-principles calculations