A study of point defects in CdIn2Te4 single crystals using photoluminescience measurements

A single crystal of p-CdIn2Te4 was grown in a three-stage vertical electric furnace using the Bridgman method. The quality of the crystal grown has been investigated by x-ray diffraction and photoluminescence measurements. From the photoluminescence spectra of the as-grown CdIn2Te4 crystal and various heat-treated crystals, (Ddegrees, X) emission was found to be the dominant intensity in the photoluminescence spectrum of the CdIn2Te4:Cd, while the (Adegrees, X) emission completely disappeared in the CdIn2Te4:Cd. However, the (Adegrees, X) emission in the photoluminescence spectrum of the CdIn2Te4:Te was the dominant intensity like in the as-grown CdIn2Te4 crystal. These results indicated that the (Ddegrees, X) is associated with V-Te which acted as a donor and that the (Adegrees, X) emission is related to V-Cd which acted as an acceptor, respectively. The p-CdIn2Te4 crystal was obviously found to be converted into n-type after annealing in Cd atmosphere. The origin of the (Ddegrees, Adegrees) emission and its transverse optical (TO) phonon replicas is related to the interaction between donors such as V-Te or Cd-int, and acceptors such as V-Cd or Te-int. Also, the In in the CdIn2Te4 was confirmed not to form the native defects because it existed in a stable bonding form.