Photoionization Cross‐Section for δ‐Shell Deep Levels

Abstract

A 6-shell model is presented of deep impurities in semiconductors as a simple but effective extension of the well-known &function model of Lucovsky, in order to address the problem of fairly sharp photo-ionization spectra. Whereas Lucovsky treated only the photo-ionization of electrons from s-like impurity states to the conduction band (forbidden transitions), this paper considers also the photo-ionization of holes t o the valence band (allowed transitions). The new %-shell model gives an improved fit to experimental photo-ionization data. It can be used to determine the range of the deep impurity potential as well as the binding energy, and can help to determine the nature of the photoionized charge (electron/hole).Ein 6-Schalenmodell tiefer Storstellen in Halbleitern zur Behandlung des Problems der ziemlich spitzen Photoionisationsspektren wird als einfache aber effektive Erweiterung des gut bekannten 8-Funktionsmodell von Lukovsky angegeben. Wiihrend Lukovsky nur die Photoionisation von Elektronen aus s-Storstellenzustanden ins Leitungsband (verbotene ifbergiinge) behandelt, wird hierbei auch die Photoionisation von Lochern in das Valenzband (erlaubte ifber-gLnge) beriicksichtigt. Das neue 6-Schalenmodell ergibt eine verbesserte Anpassung an experimen telle Photoionisationsdaten. Es 1aBt sich zur Bestimmung des Bereichs des Potentials der tiefen Storstelle sowie der Bindungsenergie benutzen und kann helfen, die Art der photoionisierten Ladung (Elektron/Loch) zu bestimmen.

Internal Cobalt States and Charge Transfer Transitions in ZnTe:Co Crystals under Pressure

“…This assignment of the observed absorption edge was also proposed by other authors [14], [15]. For p±d transitions the spectral dependence near the absorption threshold is given by [13] ahn G hn À E ct 1a2 X 3…”

Optical Absorption of Zinc Selenide Doped with Cobalt (Zn1-xCoxSe) under Hydrostatic Pressure

“…The theoretical expression derived by Masut and Penchina [27] for allowed transitions between the valence band and the deep levels has been used to fit the absorption data and to obtain a charge transfer threshold energy in those cases. Our absorption curves do not show a square root spec-Optical Absorption of Zinc Selenide Doped with Cobalt under Hydrostatic Pressure 565 Fig.…”

Systematic investigation of composition effects on the radiation-induced attenuation mechanisms of aluminosilicate, Yb-doped silicate, Yb- and Yb,Ce-doped aluminosilicate fiber preforms [Invited]

“…Such data are important to anticipate the impact of temperature or time on the optical degradation. They also determine the dependence of photobleaching cross-sections on photon energy [16]. Optical (PD loss or RIA monitoring, fluorescence) and ESR measurements are of course of crucial interest to follow the CCs evolution with temperature, dose, pumping or annealing time.…”