PHOTOLUMINESCENCE AND INFRARED TRANSMISSION SPECTROSCOPIES OF CDGEAS2

The first detailed photoluminescence (PL) study of as-grown CdGeAs2 sa mples obtained from three different sources is presented. The study wa s carried out in the 5-100 K temperature range and laser excitation de nsities 0.5-5 W cm(-2) PL spectra collected on samples from all source s showed a PL band near 355 meV which is assigned to an (e, A(0)) tran sition to the deep native double acceptor 315 meV above the valence ba nd edge. Samples from one source which contained substantially lower l evels of oxygen also had about an order of magnitude lower values of a bsorption coefficient below the band gap and showed also a single PL b and in their PL spectra.