Physical Review B 72, 245303 (2005)
| Roughness-induced mechanisms for electron scattering in wurtzite group-III-nitride heterostructures | |
| Roughness-induced mechanisms for electron scattering in wurtzite group-III-nitride heterostructures | |
| Tạp chí Physical Review B 2005 2 December 2005; 72 (24):245303 | |
| Tác giả | Doan Nhat Quanga, Nguyen Huyen Tungb, Vu Ngoc Tuocb, Nguyen Viet Minhb and Pham Nam Phongb |
| Nơi thực hiện |
a
Center
for
Theoretical
Physics,
Vietnamese
Academy
of
Science
and
Technology,
P.O.
Box
429,
Boho,
Hanoi
10000,
Vietnam
bInstitute of Engineering Physics, Hanoi University of Technology, 1 Dai Co Viet Road, Hanoi, Vietnam |
| Từ khóa | piezoelectric, strain relaxation, heterostructures, wurtzite structure |
| DOI URL PDF | |
Abstract[sửa]
We
present
a
theory
of
the
low-temperature
mobility
of
the
two-dimensional
electron
gas
(2DEG)
in
wurtzite
group-III-nitride
heterostructures,
e.g.,
AlGaN/GaN,
taking
adequate
account
of
the
roughness-induced
scattering
mechanisms
and
the
effect
due
to
sheet
polarization
charges.
The
squeeze
of
the
electron
distribution
in
the
quantum
well
by
positive
piezoelectric
and
spontaneous
polarization-induced
charges
on
the
interface
is
calculated
in
an
analytic
form.
Thus,
we
obtained
simple
expressions
describing
the
squeeze-related
enhancement
of
the
2DEG
screening
and
the
unscreened
potentials
for
different
scattering
sources.
Altogether,
their
screened
potentials
may
be
strongly
enhanced,
so
that
the
2DEG
mobility
may
be
remarkably
reduced
by
sheet
polarization
charges.
Moreover,
we
proved
that
the
roughness-induced
piezoelectric
charges
and
the
roughness-induced
deformation
potential
exhibit
new
important
scattering
mechanisms
governing
the
2DEG
transport
in
wurtzite
III-nitride
heterostructures.
The
partial
2DEG
mobilities
limited
by
them
may
be
of
the
order
of
or
less
than
.
Our
theory
turns
out
to
be
successful
in
the
quantitative
explanation
of
recent
experimental
data
about
the
high-density
2DEG
mobility,
e.g.,
its
nonmonotonic
dependence
on
carrier
density
and
its
enhancement
in
the
double
heterostructure,
which
have
not
been
understood
starting
merely
from
the
conventional
scattering
mechanisms.
