How Graphene Islands Are Unidirectionally Aligned on the Ge(110) Surface.
The unidirectional alignment of graphene islands is essential to the synthesis of wafer-scale single-crystal graphene on Ge(110) surface, but the underlying mechanism is not well-understood. Here we report that the necessary coalignment of the nucleating graphene islands on Ge(110) surface is caused by the presence of step-pattern; we show that on the preannealed Ge(110) textureless surface the graphene islands appear nonpreferentially orientated, while on the Ge(110) surfaces with natural step pattern, all graphene islands emerge coaligned. First-principles calculations and theoretical analysis reveal this different alignment behaviors originate from the strong chemical binding formed between the graphene island edges and the atomic steps on the Ge(110) surface, and the lattice matching at edge-step interface dictates the alignment of graphene islands with the armchair direction of graphene along the [-110] direction of the Ge(110) substrate.
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Jiayun
J
Dai
Department of Physics, East China Normal University , Shanghai 200241, China.
Danxia
D
Wang
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Miao
M
Zhang
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Tianchao
T
Niu
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Ang
A
Li
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Mao
M
Ye
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Shan
S
Qiao
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Guqiao
G
Ding
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Xiaoming
X
Xie
Materials Science and Technology Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
Yongqiang
Y
Wang
Department of Physics and Materials Science, City University of Hong Kong , Kowloon, Hong Kong 999077, China.
Paul K
PK
Chu
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.|Department of Physics, East China Normal University , Shanghai 200241, China.|Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
Qinghong
Q
Yuan
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Zengfeng
Z
Di
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
Xi
X
Wang
Institute of Textiles and Clothing, Hong Kong Polytechnic University , Kowloon, Hong Kong 999077, China.
Feng
F
Ding
Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
Boris I
BI
Yakobson
Graphene; alignment; chemical bonding; first-principles calculation; lattice matching; surface step