of 4
1
Supporting Information
Two-dimensional Halide Perovskites: Tuning Electron
ic Activities of Defects
Yuanyue Liu,
*1,2
Hai Xiao
1
and William A. Goddard III
*1
1
Materials and Process Simulation Center
2
the Resnick Sustainability Institute
California Institute of Technology, Pasadena, CA 91
125, USA
*
Correspondence to:
yuanyue@caltech.edu
and
wag@wag.caltech.edu
The line defects are modelled by a ribbon with widt
h of ~3 nm (for edges) or 6 nm (for grain
boundaries). For point defects in 2D Rb
2
PbI
4
, we use a 4x4 supercell (see the structure of the
primitive cell in Fig. 1). For point defects in 2D
MA
2
SnBr
4
, we use a 3x3 supercell to reduce the
computational cost to an affordable limit.
Fig. S1
. Edges along
A
direction with surplus cations/deficient anions.
A
n
+ can be thought as
adding more Rb into
A
–N+ (Fig. 2), and
A
n
- can be thought as removing I from
A
–N+, or
adding more Rb into
A
–N- (Fig. 2).
2
Fig. S2
. Edges along
Z
direction with surplus cations/deficient anions.
Z
n
+ can be thought as
adding more Rb into
Z
–N+ (Fig. 2), and
Z
n
- can be thought as removing I from
Z
–N+, or
adding more Rb into
Z
–N- (Fig. 2).
Fig. S3
. Structure of grain boundary with surplus cations.
This can be thought as adding more Rb
into GB–N (Fig. 3).
3
Fig. S4
. Energies of various edges along
Z
direction, with respect to that of Z–N+, as a func
tion
of I chemical potential (with respect to that of I2
molecule) along phase boundaries.
Fig. S5
. Energies of various grain boundaries, with respec
t to that of GB–N, as a function of I
chemical potential (with respect to that of I2 mole
cule) along phase boundaries.
4
Fig. S6
. Energies of various point defects in 2D MA
2
SnBr
4
(MA= CH
3
NH
3
), as a function of Br
chemical potential (with respect to that of Br
2
molecule) along phase boundaries. These suggest
that the formation of harmful defects can be suppre
ssed by decreasing the chemical potential of
Br, in consistence with Rb
2
PbI
4
.