Electron paramagnetic resonance studies on manganese(II)-containing zinc and cadmium sulfide materials

Abstract

Electron paramagnetic resonance (EPR) spectroscopy has been applied to investigate unusual phenomena observed in the photoluminescence of manganese(ii)containing zinc and cadmium sulfide materials. For manganese(ii) in zinc sulfide the g value and the hyperfine splitting constant are barely dependent on the type of material (polycrystalline powder, thin film, superlattice). An anomalous emission of the polycrystalline ZnS : Mn powders calcined at 90&1000°C in the vicinity of 520 nm is ascribed to manganese(ii) in an environment with a large distortion due to oxygen impurities. For the thin films and superlattices unusual EPR spectra are observed when manganese(ii) is present in cadmium sulfide: a large cubic splitting parameter of 53.8 x cm-' for the thin films of CdS : Mn on BaF2(111) reflects the strain due to different thermal expansions of cadmium sulfide and barium fluoride. A negative g-shift of 0.0014 for the superlattices of CdS : Mn-ZnS on BaF2(111) compared with that for the free electron implies that the covalency between manganese(ii) and the environment in cadmium sulfide is affected significantly by the lattice mismatch between the alternate layers of zinc and cadmium sulfides.

Preparation and Cathodoluminescence Properties of Ga-Doped ZnS Nanowalls

“…attributed to a self-activated (SA) center presumably formed by the vacancy states or the interstitial states [12,13]. The blue luminescence is most likely due to the donor-acceptor type transition between a shallow donor associated with a sulfur vacancy and a Zn 2+ vacancy-related acceptor [14]. When Ga 2 O 3 : ZnS = 1 : 10 was used as the source (Ga = 3.23 at.…”

Halide‐Transport Chemical Vapor Deposition of Luminescent ZnS:Mn2+ One‐Dimensional Nanostructures

“…This blue luminescence has been attributed to a self-activated (SA) center presumably formed between a Zn vacancy and a shallow donor associated with a sulfur vacancy. [34,35] When Zn/Mn = 4:1 was taken as the source (Mn 2.82 mol-%), the spectra show two peaks at 454 nm and 572 nm, respectively. The former was due to the SA center, while the later was attributed to the transition from 4 T 1 (G) ® 6 A 1 (S) states within the Mn center, which is discussed in detail later in this paragraph.…”

Effect of chloride on the photoluminescence of ZnS:Mn thin films

“…This blue luminescence has been attributed to a selfactivated ͑SA͒ center presumably formed between a Zn vacancy and a shallow donor associated with either a substitutional chloride atom 5,6 or a sulfur vacancy. [7][8][9] The presence of Mn leads to an extinction of the SA emission. Emission shifts at reduced temperature are affected by the increase of band gap of the host material or the position change of the energy level of dopants or defects in the band gap with a decrease in temperature.…”