Electron spin resonance identification of isolated Fe3+ in CdTe

Abstract
A new electron spin resonance (ESR) spectrum has been observed and identified in CdTe. The analysis of data taken at 9.5 and 35 GHz shows that the defect involved has cubic symmetry and spin S=5/2, and most likely corresponds to isolated Fe3+. Photo ESR results indicate that isolated iron is a deep donor with an ionization energy of (1.0±0.1) eV. Since the Fe3+ ESR has been observed in several nominally undoped samples it is concluded that iron is a common residual impurity in high‐purity CdTe.