A phenomenological model of the red luminescence kinetics in ZnTe:O

• Published in: Journal of applied physics 1987-01, Vol.61 (2), p.734-737
• Main Authors: HJALMARSON, H. P, NORRIS, C. B
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other luminescence and radiative recombination; Physics
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.338225

We previously described an efficient red luminescence in ZnTe:O which dominates the emission spectrum from liquid nitrogen to room temperatures; this luminescence has been attributed to recombination at isoelectronic O centers. Frequency-domain luminescence measurements on this band have revealed complex kinetics corresponding to fast and slow decay processes. In this paper, these kinetics are compared with the predictions of a two-step electron capture model in which recombination occurs by electron capture at the O center followed by hole capture. Although the slow decay component of the luminescence is consistent with the electron capture model, the fast transient is shown to be in qualitative disagreement with that model. It is argued that more sophisticated versions of the basic two-step capture model will not fit the data. Parallel processes in which two mechanisms contribute to the luminescence are proposed to explain the data. In particular, it is proposed that direct capture of free excitons by the O impurities together with two-step electron capture may explain the data.