Multipole Field Effects in Donor-Acceptor Spectra of GaP

Abstract

A shell substructure has been resolved by Dean, Henry, and Frosch in luminescence spectra due to donors and acceptors in GaP. We can fit the substructure by considering the multipole fields of the donor and acceptor ions. A doublet structure in the type-I spectrum due to C + O can be explained by an octupole component alone, and fitting the data yields a measure of the ionic-charge delocalization.