Preparation of CaO as OLED getter material through control of crystal growth of CaCO3 by block copolymers in aqueous solution

Abstract

It was possible to synthesize CaO nanoparticles by thermal decomposition at 600 °C for 3hr in vacuum state using CaCO3 prepared by additives (L64 or PEGPG). Especially, the effects of additives on crystal structure of CaCO3 were investigated at various experimental conditions. Moreover, the preparation method of CaO from ACC through the thermal decomposition in vacuum state was a successful pathway for the fabrication of CaO nanoparticles as OLED getter material for application in advanced OLED devices. These approaches to prepare the CaCO3 and CaO nanoparticles are attractive due to the following four reasons; (1) simple preparation of CaCO3 with various shapes and crystal structures depending upon the properties of additives (L64 or PEGPG), (2) preparation of CaO nanoparticles with perfect crystal structure at relatively low temperature (at 600 °C), (3) CaO nanoparticles with sufficient capacity of water adsorption as qualification to increase lifetime of OLED display, and (4) preparation of CaO nanoparticles for application in advanced full-sized OLED display to reduce light scattering and increase brightness. The CaCO3 and CaO particles obtained here may be promising candidates for both fundamental research and industrial applications.