Flux Bridgman growth and the influence of annealing temperatures on PL properties of ZnO single crystals

Abstract

Transparent ZnO crystals were obtained by the flux Bridgman method from high temperature solution of 22 mol% ZnO-78 mol% PbF 2 system. The influence of annealing temperatures on the photoluminescence (PL) of ZnO crystal was investigated. An ultraviolet emission peak at about 379 nm was observed in PL spectra and the peak position has a weak blueshift for annealed samples. A green band centered at 523 nm appeared in the annealed samples and its intensity enhanced with the increase of annealing temperatures, while the intensity of the ultraviolet peak decreased considerably. However, the ultraviolet emission peak became the strongest after annealing at 1000 °C. This phenomenon was considered to be associated with oxygen vacancy and F -impurities induced by the PbF 2 flux. The results show that high temperature annealing in air seems helpful for improving the PL properties of ZnO crystal.

The Effect of Green Body Pressure, Sintering Time and Electric Current on ZnO Crystal Growth by Electric Current Heating Method

“…Since ZnO has been further study in many applications, there are several techniques of fabrication that can be applied to synthesize ZnO micro/nanostructures. The common methods include hydrothermal [5], chemical vapor transport (CVT) method [6], pressurized melt method [7] and flux method [8]. These methods have been used and proven to be successful in ZnO micro/nanostructures growth.…”

Surface Morphology Study of Chemical Vapor Transport of ZnO Crystals

“…To date, bulk ZnO single crystals have been grown via a hydrothermal (HT) method [ 4 – 6 ], pressurized melt method [ 7 , 8 ], flux method [ 9 – 11 ], and chemical vapor transport (CVT) method [ 9 , 10 , 12 , 13 ]. Among them, CVT method is suitable for high-purity ZnO crystals grown at the relatively low temperature.…”