Binding Energies and Linear and Nonlinear Optical Properties of
a DonorImpurity in a Three-Dimensional Quantum Pseudodot
Muharrem Kiraka and Sait Yilmazb
a Department of Science Education, Faculty of Education, Bozok University, 66200 Yozgat,
b Department of Physics, Faculty of Arts and Sciences, Bozok University, 66200 Yozgat, Turkey
Reprint requests to M. K.; E-mail: firstname.lastname@example.org
Z. Naturforsch. 68a, 744 – 750 (2013) / DOI: 10.5560/ZNA.2013-0053
Received December 5, 2012 / revised July 11, 2013 / published online September 18, 2013
The problem of a shallow donor impurity located at the centre of a symmetrical paraboloidal quantum dot (SPQD) is solved exactly. The Schrödinger equation is separated in the paraboloidal coordinate system. Three different cases are discussed for the radial-like equations. For a bound donor, the energy is negative and the solutions are described by Whittaker functions. For a non-bound donor, the energy is positive and the solutions become coulomb wave functions. In the last case, the energy is equal to zero and the solutions reduce to Bessel functions. Using the boundary conditions at the dot surfaces, the variations of the donor kinetic and potential energies versus the size of the dot are obtained. The problem of a shallow donor impurity in a Hemiparaboloidal Quantum dot (HPQD) is also studied. It is shown that the wave functions of a HPQD are specific linear combinations of those of a SPQD.
throughput light power
I@ and deflected light power I@ are performed in the far-
field pattern of the output end-face using a photodetec-
tor. After some amplification the signal can be passed to a
X — Υ recorder, or to an oscilloscope.
First, some comments should be made on the dc drift
phenomena of the guided light. It is well known that the
laser transmission in LiNbO3 waveguides photoionizes
donorimpurities, such as divalent iron, and induces
charge separation along the crystal's polar axis .
When an external electric field Ε is applied in the wave-
expensive RuOz and silver powders are often
added in order to eliminate non-ohmic contact
and reduce room temperature resistivity. But we
used micro (Vi.xCrx)203 instead. Not only the
costs were cut down but also the room
temperature resistivity was reduced. The
accuracy and R-T curve linearity were improved
as well. So better effect was achieved. That was
another feature of this study.
5) In this study, Y 2 0 3 was not only the donorimpurity, which made Ba,.xSrxTi03
semiconductive, but also a kind of stabilizer'51,
which stopped the grains from
, Cd and Ta, it is plausible that
Sc 3 + , C d 2 + and Ta 5 + are realized in T i 0 2 .
To make the situation more clear, we now consider
the electronic structure of the T i 0 2 matrix with impu-
rities. The schematic band-structure of pure T i 0 2 is
shown in Figure 2. The Fermi level (8y) of pure T i 0 2
sits in the band gap. The valence band is mainly from
the oxygen p-states, and the conduction band is
mainly from the metal d-states. Nb atom and Ta atom
has one more valence electron than Ti atom. When
such donorimpurities are introduced in this matrix
EU PVSEC; 2010 6 – 10 Sept; Valencia,
 J. Haunschild, J. Broisch, I. Reis, S. Rein. Quality control of
czochralski grown silicon wafers in solar cell production using
photoluminescence imaging. Proc 26th EU PVSEC; 2011 5 – 9
Sept; Hamburg, Germany.
 A. S. Grove, O. Leistiko, C. T. Sah. Redistribution of acceptor
and donorimpurities during thermal oxidation of silicon.
J Appl Phys. 1964;35(9):2695 – 2701.
 J.-F. Nekarda, M. Hörteis, F. Lottspeich, A. Wolf, R. Preu.
Comparison of the three different metallization concepts
. Rev. 92, 943 (1953).
11. Wolf, H., Deubler, S., Forkel, D., Foettinger, H., Iwatschenko-
Borho, M., Meyer, F., Renn, M., Witthuhn, W., Helbig, R.: Accep-
tors and Donors in the Wide-Gap Semiconductors ZnO and SnO2.
Mater. Sci. Forum 10–12, 863 (1986).
12. Deubler, S., Meier, J., Schütz, R., Witthuhn, W.: PAC Studies on
Impurities in ZnO. Nucl. Instrum. Meth. Phys. Res. B 63, 223
13. For the origin of the fast damping in the spectra of Al-doped ZnO,
we should take into consideration the effect of a presumed local
spin provided by the donorimpurities
contact to the solution that
is only saturated with respect to the other component of the hetero-
junction. There is a limited range of solid solubility between InP and
CdS38 and the coprecipitation of both materials during the later stages
of the cooling cycle leads to mixed epilayers with undesirable properties
for solar cell applications. Cd and Sn dissolve InP much more readily
than CdS and are thus suitable solvents for liquid phase epitaxy of
InP on CdS substrates. However, only Cd generates p-type conduc-
tivity while Sn is a donorimpurity in InP and pure Sn is
. 1991). The α-Fe2O3 specimens containing donorimpurities
are n-type semiconductors at low temperature because conduc-
tion band electrons are much more mobile as charge carriers
than are valence band holes at room temperature (Goodenough
1972; Leland and Bard 1987; Anderman and Kennedy 1988;
Merchant et al. 1979). Except where stated, all samples were
imaged in air after immersion in water to help ensure that the
surface was hydrated. Samples were dried by touching a
Kimwipe the crystal edge to wick bulk water away.
Because of drift and other problems (Eggleston 1994
electron to the conduction band of the crystal, in a
manner analogous to a donorimpurity atom in a semi-
conductor, or to an F' center in an alkali halide23.
To be a little more specific, one could think of this
ionization as the trapping of a positive hole. If on
recoil an electron transfer took place
Recoil Co*++ + CO(NH3)„+++ + NO,- ^ Co++ + Co*(NH3)e++
Recoil Br*" + Co(NH3)5Br++ -> Br° + Co(NH3)5Br*+
then one would have a defect (the complex ion of
cobalt [II]) and a nearby positive hole (Br° or N 0 3 ° ) so
tha t on supplying the necessary