10.1021/acs.jpcc.7b07642.s001
Hefei Wang
Hefei
Wang
Chen Si
Chen
Si
Jian Zhou
Jian
Zhou
Zhimei Sun
Zhimei
Sun
Vanishing Schottky Barriers in Blue Phosphorene/MXene
Heterojunctions
American Chemical Society
2017
2 D semiconductors
MXene
OH
electrode material
Schottky barrier characteristics
heterojunction
Hf
Nb-based 2 D transition metal carbides
2 D semiconductor
Schottky barriers
Zr
terminal surface groups
BlueP
Vanishing Schottky Barriers
2017-10-31 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Vanishing_Schottky_Barriers_in_Blue_Phosphorene_MXene_Heterojunctions/5573362
An
appropriate electrode material is crucial for two-dimensional
(2D) semiconductors, where a vanishing Schottky barrier is ideal but
is a great challenge. Blue phosphorene (BlueP) is a promising 2D semiconductor
for electronic and optoelectronic applications. Here, we report that
Zr-, Hf-, and Nb-based 2D transition metal carbides (MXenes) are ideal
electrode materials for BlueP based on extensive investigations of
the electronic properties and interfacial Schottky barrier characteristics
of BlueP/MXene heterojunctions by first-principles calculations. Our
results show that the strong interaction between BlueP and bare MXenes
destroys the semiconducting character of BlueP, and thus bare MXenes
are not ideal contact electrodes. With the surface functionalization
of MXene, the intrinsic electronic feature of BlueP is well preserved
in the BlueP/surface-engineered MXene heterojunctions. Furthermore,
the interfacial Schottky barriers of the heterojunctions are affected
by the terminal surface groups on MXenes, and vanishing Schottky barriers
are achieved in some MXenes with the formula Zr<sub><i>n</i>+1</sub>C<sub>n</sub>F<sub>2</sub>, Hf<sub><i>n</i>+1</sub>C<sub><i>n</i></sub>F<sub>2</sub>, Zr<sub><i>n</i>+1</sub>C<sub>n</sub>(OH)<sub>2</sub>, Hf<sub><i>n</i>+1</sub>C<sub><i>n</i></sub>(OH)<sub>2</sub>, and Nb<sub><i>n</i>+1</sub>C<sub><i>n</i></sub>(OH)<sub>2</sub>.
Finally, we demonstrate that the work functions of MXenes and the
interface dipole induced by charge rearrangement are two underlying
factors to determine the magnitude of Schottky barriers. This work
provides fundamentals for selecting ideal electrode material for BlueP
and is also beneficial for optimizing electrodes for other 2D semiconductors.