Vortrag: Properties of Solid State Devices with Mobile Ionic Defects

Vortrag im Fakultätskolloquium am 18.10.

Im Rahmen des Fakultätskolloquiums findet am
Mittwoch, dem 18.10.06, um 16 Uhr s.t., im Kleinen Hörsaal des Instituts für Physik und Physikalische Technologien, Leibnizstrasse 4,
folgender Gastvortrag statt:

Properties of Solid State Devices with Mobile Ionic Defects - The effects of motion, space charge and contact potential in Metal/Semiconductor/Metal devices
Prof. I. Riess, Physics Department, Technion-IIT, Haifa, Israel

As devices become smaller the question of motion of the acceptors and donors under dc current and extended periods of time becomes more acute.
In nano devices the driving forces are significantly higher than in marco ones, as the chemical or electrical potential differences have a typical value of 0.1-1 eV or volt while they appear over a much smaller distance. Furthermore, the diffusion length required in order to significantly alter the defect concentration is much smaller.
We have therefore examined the redistribution of defects in a mixed ionic electronic device under steady state, dc, current and its effect on the I-V relations. The solid state device examined is based on a p-type semiconductor with mobile acceptors. The device is a basic one of the form: Metal|Semiconductor|Metal. The metal electrodes are assumed to be chemically inert and to block material exchange. The effects of the contact potentials as well as of the space charge are taken into consideration. The motion of the acceptors is found, in some cases, to introduce only minor changes in the I-V relations. This finding may be of significance for solid state devices of reduced scale. The I-V relations of samples much thicker than the equilibrium Debye length reduce to the ones obtained assuming local neutrality throughout the sample. The results also depend significantly on the reaction constant between the acceptors and holes to form neutral acceptors.

Nachrichtenalter: 13.10.2006 14:05


Kontakt  Suche  Sitemap  Datenschutz  Impressum  Verantwortlich: Florian Voigts
© TU Clausthal 2022