I can not obtain the n/p-type transport of graphene at 1E15 cm-2

[guodonglin]

Dear Developer

For n/p-type transport of graphene, i set "ncarrier = -1E15" or "ncarrier = 1E15" in epw.in file, but the final concentration is about 1E13 cm-2. This problem has puzzled me for a long time. I don 't know how to solve this problem.

--
&inputepw
prefix = 'graphene'
amass(1) = 12.01078
amass(2) = 12.01078
outdir = './out'

elph = .true.
epbwrite = .false.
epbread = .false.
epwwrite = .false.
epwread = .true.

etf_mem = 3
mp_mesh_k = .true.
lpolar = .false.
vme = 'dipole'

use_ws = .false.
lifc = .false.

nbndsub = 10
system_2d = 'gaussian'

scattering = .true.
scattering_serta = .true.
int_mob = .false.
carrier = .true.
ncarrier = -1E15
iterative_bte = .true.
epmatkqread = .false.
mob_maxiter = 3000
broyden_beta = 1.0
bfieldx = 0.0d0
bfieldy = 0.0d0
bfieldz = 1.0d-10

nstemp = 1
temps = 300

restart = .true.
restart_step = 1000
selecqread = .false.

wannierize = .false.
num_iter = 5000
iprint = 2
dis_win_max = 8.0
dis_win_min = -25
dis_froz_max = -1
proj(1) = 'C1:sp2;pz'
proj(2) = 'C2:pz'

wdata(1) = 'bands_plot = .true.'
wdata(2) = 'begin kpoint_path'
wdata(3) = 'G 0.00 0.00 0.00 M 0.50 0.00 0.00'
wdata(4) = 'M 0.50 0.00 0.00 K 0.333333333333 0.333333333333 0.00'
wdata(5) = 'K 0.333333333333 0.333333333333 0.00 G 0.0 0.0 0.00'
wdata(6) = 'end kpoint_path'
wdata(7) = 'bands_plot_format = gnuplot'
wdata(8) = 'dis_num_iter = 5000'
wdata(9) = 'num_print_cycles = 10'
wdata(10) = 'dis_mix_ratio = 1.0'
wdata(11) = 'conv_tol = 1E-12'
wdata(12) = 'conv_window = 4'
iverbosity = 3 ! epw.out

elecselfen = .false.
phonselfen = .false.
a2f = .false.

dvscf_dir = './save'
fsthick = 3.0
degaussw = 0.0 ! eV (adaptative smearing)
ngaussw = -99
efermi_read = .true
fermi_energy = -4.228393


nkf1 = 120
nkf2 = 120
nkf3 = 1
nqf1 = 120
nqf2 = 120
nqf3 = 1

nk1 = 12
nk2 = 12
nk3 = 1
nq1 = 12
nq2 = 12
nq3 = 1
/


Iteration number: 55

=============================================================================================
Temp Fermi Hole density Population SR Drift Hole mobility
[K] [eV] [cm^-2] [h per cell] [cm^2/Vs]
=============================================================================================

300.000 -6.8129 0.14724E+14 -0.10244E-01 0.124984E+05 -0.108275E+00 0.000000E+00
0.39565E-07 -0.676958E-01 0.124984E+05 0.000000E+00
0.00000E+00 0.000000E+00 0.000000E+00 0.000000E+00

0.000000E+00 Max error


Iteration number: 20

=============================================================================================
Temp Fermi Elec density Population SR Drift Elec mobility
[K] [eV] [cm^-2] [e per cell] [cm^2/Vs]
=============================================================================================

300.000 -1.9614 0.10759E+14 0.65273E-01 0.453374E+05 0.560650E+01 0.000000E+00
-0.56684E-05 0.562513E+01 0.453374E+05 0.000000E+00
0.00000E+00 0.000000E+00 0.000000E+00 0.000000E+00

0.000000E+00 Max error

=============================================================================================
Summary and Hall factor
=============================================================================================

[stiwari]

Hi,

Can you try increasing the fine-grid (nkf and nqf)? If that does not work can you attach your input and output files?

Best regards,
Sabya.

[Zhe_L]

Hi,

I have two comments on the input file.

1. 1.E-15 cm^-2 is far too large for a 2 dimension system. It can be found that the doped Fermi level ( -6.8129 and -1.9614) is far from the input one (-4.228393)
2. As we know, graphene is a semi-metal, which is incompatible with carrier and ncarrier. They are for semi-conductors only.

Best,
Zhe