I am not getting the correct characteristic in reverse bias even after using impact ionization model.

I am Attaching my code and result for reference.

go atlas

# MESHING SECTION

mesh

x.mesh loc=0 spac=0.1

x.mesh loc=1 spac=0.1

y.mesh loc=0 spac=0.1

y.mesh loc=5 spac=0.001

y.mesh loc=10 spac=0.1

# REGION SECTION

region num=1 y.min=1 y.max=5 mat=silicon

region num=2 y.min=5 y.max=9 mat=silicon

# ELECTRODE SECTION

electrode name=anode y.min=0 y.max=1 mat=Aluminium

electrode name=cathode y.min=9 y.max=10 mat=Aluminium

# DOPING SECTION

doping p.type conc=1e19 uniform reg=1

doping n.type conc=1e16 uniform reg=2

# MATERIAL PROPERTIES

material region=1 taun0=1e-6 taup0=1e-6 augn0=2.8e-31 augp0=9.9e-32 eg300=1.12 nv300=2.51e19 nc300=6.62e19 affinity=4.05 permittivity=11.9 mun0=1500 mup0=450

material region=2 taun0=1e-6 taup0=1e-6 augn0=2.8e-31 augp0=9.9e-32 eg300=1.12 nv300=2.51e19 nc300=6.62e19 affinity=4.05 permittivity=11.9 mun0=1500 mup0=450

# METHOD

model srh auger bgn impactselb print

method newton

output e.field band.param con.band val.band

solve init

struct outf=Gagan_Si_diode.str

tonyplot Gagan_Si_diode.str

log outfile=Gagan_Si_diode.log

solve vanode=0 vstep=-0.1 vfinal=-12 name=anode

tonyplot Gagan_Si_diode.log

#

quit