Te Antisite Incorporation In Zns1-Xtex Thin Films

We investigate Te-related intrinsic defects in ZnS1-xTe1 thin films, First-principles calculations were performed for ZnS with Te as impurity atoms. The results show that the substitutional incorporation of Te in group VI sites cannot form defect states deep in the energy band gap of ZnS. On the other hand, Our calculations on both Te antisite and interstitial defects result in deep-level states. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) were used to study the chemical structure.,, of, three molecular-beam-epitaxy-grown ZnS1-xTex samples. x{0.005,0.019,0.026}. An asymmetry was detected in the XPS spectra of both Te 3d(3/2) and Te 3d(5/2) Core levels, which indicates that a small portion of the incorporated Te atoms is bonded to a more electronegative element. A peak at m/z of 158 was detected in the SIMS depth profiles of these samples and its characteristics match that of TeS components of the lattice matrix. This experimental evidence strongly supports the existence of Te antisite defect,, in the thin films, We believe that the origin of the highly luminescent centers in ZnS1-xTex thin films is possibly attributed to the deep-level states generated from Te anti-site incorporation.