dc.contributor.author | Oyoko, Hannington O | |
dc.date.accessioned | 2013-09-26T06:25:30Z | |
dc.date.available | 2013-09-26T06:25:30Z | |
dc.date.issued | 1991-05 | |
dc.identifier.citation | Oyoko,H.O.,May,1991.DONOR STATES IN A GaAs/Ga1_xAlxAS QUANTUM WELL WIRE OF CIRCULAR CROSS SECTION. | en |
dc.identifier.uri | http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/56712 | |
dc.description.abstract | The present work considers the donor states in a
GaAs/Ga1 Al As QWW of circular cross section. Several
trial wave functions are used to describe the ground state
of the donor impurity. Using these trial wave functions the
binding energy of the donor impurity in the ground state is
determined for the hydrogenic case €(o), and for the
non-hydrogenic case, €(r).
The binding energy for the first excited state is also
determined using a trial wave function which is orthogonal
to the ground state trial wave function. Here again the
calculation is carried out for the hydrogenic case €(o), and
for the non-pydrogenic case €(r).
It is found that in the ground state the binding energy
i~creases with dec~~asing QWW radius for both the hydrogenic
(€(o» -and non~hydrogenic (€(r» cases. However, the
binding energy increases much more rapidly with QWW radius
in the non-hydrogenic than in the hydrogenic case. The
spatial dielectric function leads to substantially enhanced
binding energy.
For the first excited state the binding energy also
increases with decreasing QWW radius but here the screening
effect of €(r) is negligible.
It is seen from the present work that the binding
energy of a donor in a GaAs/Ga1 Al As increases with
decreasing QWW radius and that for the ground state binding
energy it is sensitive to the screening effect of €(r).
This is because in the first excited state the donor
electron does not approach the impurity ion as closely as in
the ground state. | en |
dc.language.iso | en | en |
dc.publisher | University of Nairobi | en |
dc.title | Donor states in a gas s/Ga1_xAlxAS quantum well wire circular cross section | en |
dc.type | Thesis | en |
local.publisher | College of Biological and Physical Sciences | en |