Y3Al5O12 : Ce3+형광체의 색변환층을 이용한 백색 유기발광소자의 색변환 메커니즘

Abstract

White organic light-emitting devices (WOLEDs) have been currently receiving considerable attention because of their potential applications in full-color displays, backlights for liquid crystal displays, and solid-state lighting sources. When WOLEDs have been fabricated utilizing multiple emitters in WOLEDs, the manufacturing cost of the WOLEDs is very expensive. After inorganic blue light-emitting devices (LEDs) with a color-conversion phosphor layer have been introduced, blue organic light-emitting devices (OLEDs) with color conversion material as a down conversion layer have been deposited to the opposite side of the OLEDs, Even though some studies related to fabrication of WOLEDs consisting of blue OLED with a color-conversion phosphor layer have been conducted, their efficiency, color coordinates, and color rendering indexes are not enough to apply to the utilization as backlights or general lighting sources. Therefore, systematic studies on the optical properties of WOLEDs fabricating utilizing a phosphor color conversion layer are necessary for improving device efficiency. This paper reports data for the fabrication and the optical properties of WOLEDs utilizing a color conversion layer consisting of Y3Al5O12 : Ce3+ phosphor. X-ray diffraction (XRD) measurements were performed to identify the crystallinity of the Y3Al5O12 : Ce3+ phosphor layer synthesized by using a sol-gel method. Field emission scanning electron microscopy (FE-SEM) measurements were carried out to investigate the crystal shape of the phosphor. Excitation and emission measurement were performed to investigate the optical property of the Y3Al5O12 : Ce3+ phosphor layer. Electroluminescence (EL) measurements were performed to clarify the emission color of the OLEDs with Y3Al5O12 : Ce3+ phosphor color conversion layers with different thicknesses.