Controllable photoluminescence by melting-process temperature in SnO-containing glass

Abstract

We prepared SnOZnOB 2 O 3 system glasses by means of melt-quenching technique with different melting-process temperatures in range of 11001500°C, and examined the impact of the process temperature on photoluminescent (PL) property. The glass obtained at 1100°C showed clear PL band at ³2.8 eV at room temperature. As elevating the process temperature, a shoulder appeared at lower-energy side of the PL band, and eventually broad band with peak at ³2.2 eV developed, resulting the clear orange PL. We demonstrated that the PL-color is controllable from blue to orange via white by change in the process temperature.©2015 The Ceramic Society of Japan. All rights reserved.Key-words : Glass, Photoluminescence, Zinc borate [Received March 25, 2015; Accepted May 1, 2015] Light-emitting material has been strongly required to meet various requirements owing to a diversity of our life-styles. Basically, phosphor powder is synthesized by addition of emissive ions based on ff and/or fd transition into host crystal, and is used in fluorescent lamp, plasma display and so on. Recently, PL-color tuning has a significant importance in phosphor material in terms of the variety of PL-color and color rendering for white-LED. In order to achieve them, co-and tri-doping of rare-earth (RE)/transition-metal ions has been considered. 1)3) Glass material has high optical transparency and shape-imparting on the basis of random structure, which allows the material to acquire the practical and engineering usages. Furthermore, since glass material is prepared through the mixing process of startingmaterials, e.g., glass-former and glass-modifier, and subsequent melting-process, it is quite suitable for mass-production. Therefore, photoluminescent (PL) property of oxide-glasses is examined extensively to apply them to phosphor material. 4)11)If once composition of glass is decided, the network-structure and physical property are settled in principle. Nevertheless, researcher experimentally knows that some properties of glass largely depends on the synthesis environment/condition. For example, the melting-process temperature significantly affects the crystallization, coloration and defect structure.12)14) This leads us to expect that the process temperature also affects the PL property. The process temperature is an easily-variable parameter in glass synthesis. Therefore, in this study we examined the effect of melting-process temperature on PL property in emissive glass material aiming to control the PL-color without any RE-doping.SnO-containing glass has absorbed much attention because the glass possess a large quantum-yield (QY) for visible blue-PL caused by T 1 S 0 relaxation based on s and consequently SnO-containing glass is regarded as a possible candidate for RE-free phosphor and scintillator material. 8),16) In addition, glass in ZnOB 2 O 3 system, which consists of a typical strong former, is frequently studied from optical/spectroscopic point of view. 17),18) Therefore, nominal composition of test glass in this study was determined to b...