Luminescence in highly conductive n-type ZnSe

Abstract

We have studied the photoluminescence of ZnSe doped by diffusion of Al at high temperature (1000–1100 °C) or by Ga at low temperature (600 °C). The diffused samples are highly conductive (0.1<ρ<10 Ω cm). According to the doping conditions the luminescence, at 300 °K, is dominated by the well-known self-activated orange emission (6300 Å) or by a yellow-green band that we assign to Na-Al complexes. Annealing in zinc atmosphere was found to have a large influence on the photoluminescence of the Ga-doped samples only. Thus, at 300 °K, the annealed samples exhibit a blue intrinsic emission with a strong reduction of the orange or the yellow-green bands; at 77 and 4.2 °K the photoluminescence spectra are dominated by blue lines corresponding, respectively, to free-electron–acceptor or donor-acceptor recombinations. We show that the shallow acceptor involved is Na.

En route to electrically pumped broadly tunable middle infrared lasers based on transition metal doped II–VI semiconductors

“…It was visible even with the naked eye. Some authors assign this emission to V Zn -Al complex in conductive crystals [50].…”

“…The n-type samples were obtained by subsequent diffusion of Al impurities [50,51]. The crystals were placed on top of mixture of Zn and Al powders (97 wt% of Zn and 3 wt% of Al), and again placed in identical evacuated ampoules.…”

Optical and Electrical Properties of Iodine Doped n-Type ZnSe Crystals

“…The exact nature of recombination responsible for the orange band is not perfectly understood, but it is proposed to be a donor-acceptor recombination. So far two models have been proposed: VZ n associated with ionized donor form a (i) (Vi; -D+)0 or (ii) (1' D+) -complex [5]. It is observed for ZnSe doped with VII group elements that PL spectra are shifted towards higher energies in comparison with III group.…”

A study of the growth rate of ZnSe epilayer on GaAs substrate using vapor phase epitaxy

“…One of the potential materials for blue LED's is the ZnSe semiconductor compound [1,4,9,12], because of its wide and direct band gap of about 2.67 eV [2] at room temperature. However, controlling the electrical and optical properties of the ZnSe compound is difficult because it is strongly influenced by unintentionally introduced impurities and defects.…”