Photonic crystals in biology

Poster Session, Tuesday, June 15
Theme A1 - B702
Effects of External Fields on Semiconductor Two-Dimensional Structures
Figen Karaca Boz , 1* Bahadr Bekar 2 and Saban Aktas 1
1 Department of Physics, Trakya University, Edirne 22030, Turkey
2 Kean Vocational College, Trakya University. Edirne –Kean 22800, Turkey
Abstract—We have investigated the presence of the laser and the electric fields on semiconductor two-dimensional structures.
The ground state energy has been calculated with finite different method under effective mass approximation. Within a
variational scheme, the binding energy is obtained as a function of the laser dressing parameter for the different electric field
values. The results show that the electronic properties strongly depend not only on the laser dressing parameter, but also on the
applied electric field and the shape of the semiconductor two-dimensional structure.
In recent years, there has been much interest in the study
of the laser and electric field effects on the electronics
properties of the semiconductor two-dimensional structure [1-
4]. The advances in experimental progress has made possible
the fabrication of two-dimensional semiconductor (quantum
well) which impose quantum confinement in one directions to
a charge carrier. The quantum wells (QWs) with several of
confining potential shapes such as square, parabolic, graded,
inverse parabolic, V- and inverse V-shaped have been studied
by many researchers [5-8]. These studies have been shown
that the applied of an electric field to these structures causes a
polarization of the carrier distribution. It has been reported
that the binding energy of an on-center impurity in lowdimensional
systems decreases with increase of the laser
dressing parameter.
In this work, the binding energy is investigated as a
function of the laser dressing parameter for the different
electric field values for various QWs. Fig. 1 shown the laser
dressed potential for different values of the laser parameter for
the double square QW. The barrier height is given as V=
39.30R*. As seen from the figure, the potential shape of the
double square QW changes depend on the laser parameter.
x
,V x
1,0
0,8
0,6
0,4
0,2
0,0
-1,0 -0,8 -0,6 -0,4 -0,2 0,0 0,2 0,4 0,6 0,8 1,0
x
0 a*
0 a*
0 a*
a*
0 a*
Figure 1: The laser-dressed potential of the double square QW for
different values of the laser parameter.
The variation of the binding energy as a function of the
laser dressing parameter in double square QW with the well
width 1a* and the barrier width 0.4a* for different electric
field values given in Fig.2. As the laser dressing parameter
increases, the magnitude of the binding energy decreases.
E B
(R*)
11,2
10,8
10,4
10,0
9,6
9,2
F= 0 kV/cm
F= 20 kV/cm
F= 40 kv/cm
F= 60 kv/cm
Z i
= 0 a*
8,8
0,0 0,1 0,2 0,3 0,4 0,5
a*
Figure 2: The binding energy as a function of laser parameter for different
values of the electric field.
In summary, we showed that the changes in energy can be
controlled by changing the laser dressing parameter together
with electric field. These results might be providing important
results in the device applications. This work was partially
supported by Trakya University under Grant No. TUBAP 739-
754-759-886-929-2008(58).
.
*Corresponding author: figenb@trakya.edu.tr
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6th Nanoscience and Nanotechnology Conference, zmir, 2010 307