Excitonic emission in cadmium telluride

Abstract

The photoluminescent properties of free and bound excitons in high-purity p-and n-type CdTe single crystals are investigated in detail in connection with the dependence on excitation intensity, temperature, impurity-doping, and uniaxial stress. Intense free-exciton emission is observed in the single crystals grown from solutions and vapor epitaxial methods. From the thermal dissociation processes and the analysis on the basis of the effective mass argument developed by Sharma and Rodriguez and by Hopfield, an assignment of exciton emission lines is tried.Die Photolumineszenz freier und gebundener Exzitonen in hochreinen p-nnd n-leitenden CdTe-Einkristallen wird ausfiihrlich mit der Abhangigkeit von Anregungsintensitat, Temperatur, Storstellendotierung und uniaxialer Spannung untersucht. In Einkristallen aus Losungen und mit epitaktischen Methoden aus der Dampfphase wird eine intensive Emission freier Exzitonen beobachtet. Aus dem thermischen DissoziationsprozeB und der Analyse auf der Grundlage effektiver Massen nach Sharma und Rodriguez sowie Hopfield wird eine Zuordnung der Exzitonen-Emissionslinien angegeben. 1) Very recently, Suga et al. [19] have investigatedthe Zreman effect on bound excitons t o a neutral donor.

Exciton emission of ytterbium‐implanted cadmium telluride

“…The emission polarized with the electric vector parallel or perpendicular to the direction of stress was examined, but no splitting could be detected for either the I,-or the IYb-emission peaks. Applying the same stress to an unimplanted sample produced no change in the I,-exciton emission intensity but caused the emission to shift to longer wavelengths, as observed by Taguchi et al [6]. Our stress experiments on implanted samples are a t an early stage and are being continued.…”

Study of the photoluminescence emission line at 3.33 eV in ZnO films

“…In Ref. 38, the superlinearity of the BE emission was believed to arise from enhancement in the population of binding sites due to the neutralization of donors and acceptors by photoexcited carriers. Alternatively, it was suggested that the density of binding sites for BEs was constant with varying laser power and instead the observed superlinear power dependence of the exciton emission was due to the formation of excitons from free electrons and holes.…”

The melt-growth and characterization of cadmium telluride

“…The grain boundaries in InSb for example have been systematically investigated by Haasen [29] and almost all the boundaries in a crystal have been shown to figure 8. At 5 K one can see near the band edge the donor exciton line at 1.5913 eV together with the acceptor exciton line at 1.5884 eV line [32,33]. The pairs.…”