Se‐Se isoelectronic centers in high purity CdTe

Abstract

We evidence zero‐dimensional exciton states trapped on isoelectronic Se centers in CdTe quantum wells, δ‐doped with Se. Thanks to special precautions taken to have very high purity CdTe heterostructures, it is possible to observe, in photoluminescence spectra, sharp discrete lines arising from individual centers related to the Se doping. These emission lines appear at about 40 meV below the CdTe band gap energy. The most prominent lines are attributed to the recombination of excitons bound to nearest‐neighbor selenium pairs in a tetrahedral CdTe environment. This assignment is confirmed by a common linear polarization direction of the emitted light, parallel to <110>. These excitons localized on individual isoelectronic traps are good candidates as single photon emitters (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)