Concept of Force Variation Due to Charged Defects in Elemental and Compound Semiconductors

Abstract

Green's fcnction calculations of force variation due t o charged impurities in elemental and compound seniiconductors are analysed on the basis of simple physical arguments. It is strongly suggested that the trends of force variation may not be related with the long range Coulomb interactions, however, the important criteria should be the effect of electric field of charged impurity on its nearest neighboiir bonds that mainly affects the short range couplings.Some new experimental results by i.r. method due to Si and CI impurities in CdTe are also included that lend additional justification t o t h e arguments.Rechnungen inittels Greenscher Funktion fur die Kraftanderung infolge geladener Storstellen in Element-und Verbindungshalbleitern werden auf der Grundlage von einfachen physikalischen Argumenten analysiert. Es wird angenommen, dall die Trends der Kraftanderungen nicht mit, langreichwcitigen Coulombwechselwirkungen verknupft zu sein brauchen, daB jedoch das wesentliche Kriteriiim der EinfluB des elektrischen Feldes der geladenen Storstelle auf die Bindung seiner nachsten Nachbarn sein sollte, der hauptsachlich die kurzreichweitige Kopplung beeinflullt. Einige neue experimentelle Ergebnisse durch IR-Methoden von Si-und C1-Storstellen in CdTe werden ebenfalls angegeben, die eine zusatzliche Rechtfertigung fur die Argumente liefern.

Impurity Vibrational Properties of Ga in InP Crystals

“…A thorough analysis accomplished by Vandevyver et al [4 to 71 has shown that the force variation between the impurity and its nearest neighbours depends on both the nature of the impurity (isoelectronic substitution, donor or acceptor state) and the kind of the lattice site on which the substitution is made (anion or cation site). More recently the same authors [7] have pointed out that there is a net correlation between the force constant changes around the impurity and the modification of the bond ionicity.…”

Infrared Studies of Defects in ZnS Crystals Double‐Doped with Li and Al, Ga, and In

“…I n a recent report Vandevyver et al [17] expressed the view that the change in force constants produced by the charged impurity in the crystals investigated by them can be ascribed mainly to the effect of the electric field of the impurity on its bonds with its nearest neighbours. This effect consists in a redistribution of the charge in the neighbourhood of the charged impurity, which results in a change of the degree of covalency (ionicity) of the bond.…”

On the nature of vibrations in diatomic lattices

“…It is also necessary because this solution provides the mathematical basis to obtain the frequencies of the localised modes in a diatomic linear chain with different models of local imperfection. These findings can be compared with experimental results and are important because attempts to give an adequate and general theory meet great difficulties with other mathematical methods and crystal models [29]. The purpose of this paper is to present a more direct and intuitively obvious method to examine the lattice dynamics for a one-dimensional diatomic lattice with nearest-neighbour interactions via the standard mathematical techniques of solving finite difference equations [26,30].…”