The group IB impurities (Cu, Ag, and Au) incorporated into II-VI zinc blende hosts of ZnTe and CdTe exhibit well resolved excitation lines followed by a photoionization continuum in their infrared absorption spectra. They are associated with transitions from a 1s-like ground state to various p-like excited state characteristic of a hole bound to a Coulomb center. Their spacing agree well with those predicted in the effective mass theory for single acceptors as expected for group IB elements substitutionally replacing the group IIB cations of the host. The occurrence of the simultaneous excitation of the Lyman transitions in combination with the zone center longitudinal optical phonon and hence lying in the photoionization continuum and displaying Fano-like asymmetries are features described and interpreted.
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