666de878ad
git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@10558 f3b2605a-c512-4ea7-a41b-209d697bcdaa
66 lines
2.2 KiB
Plaintext
66 lines
2.2 KiB
Plaintext
# needs description
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# DESCRIPTION: haynes-schockley
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# continuity eqn: n,t = J,x + (G-R) = D n,xx + mu (n E),x + G - 1/tau (n - n_0)
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# w/ J = D n,x + mu n phi,x
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# poisson eqn for E-field: epsilon phi,xx = -e (n - p + N_D - N_A)
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# w/ E = phi,x
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# NOTE: does not conserve electrons even with fixed E field and zero mobility
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# if J=0 --> n,x = mu/D n phi,x
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echo both
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units metal
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variable E equal 10.0
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variable n0 equal 0.0001
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variable dn equal 2.0*${n0}
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variable dt equal 0.0000001
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timestep ${dt}
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atom_style atomic
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lattice fcc 1.0
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region simRegion block -50 50 0 1 0 1
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boundary f p p
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create_box 1 simRegion
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mass 1 1.0 # need to keep this
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atom_modify sort 0 1
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# ID group atc PhysicsType ParameterFile
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fix AtC all atc drift_diffusion Si_ddm.mat
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# ID part keywords nx ny nz region
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fix_modify AtC mesh create 100 1 1 simRegion f p p
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fix_modify AtC mesh create_nodeset lbc -50.1 -49.9 -INF INF -INF INF
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fix_modify AtC mesh create_nodeset rbc 49.9 50.1 -INF INF -INF INF
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# fix a temperature
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fix_modify AtC initial temperature all 300.0
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fix_modify AtC initial electron_temperature all 300.0
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fix_modify AtC initial electron_density all gaussian 0 0 0 1 0 0 5.0 ${dn} ${n0}
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# isolate system:
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# diffusion: dn/dx = 0
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# drift : n = 0
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fix_modify AtC fix electron_density lbc ${n0}
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fix_modify AtC fix electron_density rbc ${n0}
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fix_modify AtC fix electric_potential all linear 0 0 0 $E 0 0 1
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variable perm equal 0.06
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variable nD equal 1.0e-4
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fix_modify AtC source electric_potential all ${nD}
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variable s equal 10
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thermo $s
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# f_AtC:1 thermal energy, 2 avg T, 3 electron energy, 4 avg Te, 5 total n
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thermo_style custom step cpu f_AtC[1] f_AtC[2] f_AtC[3] f_AtC[4] f_AtC[5]
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thermo_modify format 1 %5i format 2 %7.2g
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fix_modify AtC output no_atoms_ddmFE $s text
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fix_modify AtC extrinsic electron_integration implicit
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run 40
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# free electric field and allow shielding
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fix_modify AtC unfix electric_potential all
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fix_modify AtC fix electric_potential lbc linear 0 0 0 $E 0 0 1
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fix_modify AtC fix electric_potential rbc linear 0 0 0 $E 0 0 1
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fix_modify AtC extrinsic electron_integration implicit 10
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run 40
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