[Pw_forum] Surface Passivation in slabs of III-V material using pseudo hydrogen

[Piyush Kumar]

Dear all,

I am trying to calculate the bandstructure of InAs slab using QE-5.1.1.
But, I am getting lots of surface states. I tried hydrogen passivation, but
it did not work. In one paper [1], it has been mentioned that to passivate
the surface dangling bonds in III-V materials, we need to use pseudo
hydrogen atoms having fractional charges. I found this feature in another
DFT tool called ATK (
http://quantumwise.com/documents/tutorials/latest/InAs-2D/index.html/chap.slab.html),
but did not understand how to do the same in Quantum Espresso.

[1] Li, J., & Wang, L. W. (2005). Band-structure-corrected local density
approximation study of semiconductor quantum dots and wires. Physical
Review B, 72(12), 125325.

Here is my input file for bands

&control
 calculation = 'bands',
 prefix = 'inas',
 pseudo_dir = '/home/piyukr/Software/QE/upf_files/',
 outdir = '/home/piyukr/quantum_espresso/inas_slab/six_layer/tmp/'
/
&system
 ibrav=0,
 celldm(1)=8.095332,
 nat=16,
 ntyp=3,
 ecutwfc=60,
 ecutrho=480,
 occupations='smearing'
 smearing='gauss'
 degauss=0.001,
/
&electrons
 mixing_beta = 0.7,
 conv_thr =  1.0d-10,
/
ATOMIC_SPECIES
 As 74.921600   As.pbe-n-rrkjus_psl.0.2.UPF
 H 1.007940     H.pbe-rrkjus_psl.0.1.UPF
 In 114.818000  In.pbe-dn-rrkjus_psl.0.2.2.UPF
ATOMIC_POSITIONS crystal
 As 0.500000 0.000000 0.301627
 In 0.500000 0.500000 0.341301
 As 0.000000 0.500000 0.380976
 In 0.000000 0.000000 0.420651
 As 0.500000 0.000000 0.460325
 In 0.500000 0.500000 0.500000
 As 0.000000 0.500000 0.539675
 In 0.000000 0.000000 0.579349
 As 0.500000 0.000000 0.619024
 In 0.500000 0.500000 0.658699
 As 0.000000 0.500000 0.698373
 In 0.000000 0.000000 0.738048
 H  0.247778 0.000000 0.757709
 H -0.247778 0.000000 0.757709
 H  0.252222 0.000000 0.281966
 H  0.747778 0.000000 0.281966
CELL_PARAMETERS
1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 8.911321
K_POINTS crystal_b
3
0.5 0.0 0.0 30
0.0 0.0 0.0 30
0.5 0.5 0.0 1

I am also attaching my bandstructure.


Thanking you,
Piyush Kumar
M.Tech. Student
Indian Institute of Technology (IIT) Kanpur,
India
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