White light emitting diodes (WLEDs) were made by coating organic and inorganic hybrid composites on blue LED chips. Y3Al5O12:Ce (YAG:Ce) nano powder prepared by lowtemperature Sol-Gel method exhibited a broadband green emission spectrum with the peak at 521 nm. | Communications in Physics, Vol. 23, No. 1 (2013), pp. 57-63 ORGANIC – INORGANIC HYBRID LUMINESCENT COMPOSITE FOR SOLID-STATE LIGHTING DO NGOC CHUNG, LE TRAC TUAN, TRAN CONG HAO, DO NGOC HIEU, AND NGUYEN NANG DINH University of Engineering and Technology, Vietnam National University Hanoi PHAM HONG DUONG Institute of Materials Science, Vietnam Academy of Science and Technology Abstract. White light emitting diodes (WLEDs) were made by coating organic and inorganic hybrid composites on blue LED chips. Y3 Al5 O12 :Ce (YAG:Ce) nano powder prepared by lowtemperature Sol-Gel method exhibited a broadband green emission spectrum with the peak at 521 nm. The white light was obtained by mixing blue light from emission of the blue LED chip Indium Gallium Nitride (InGaN), green-red light from the fluorescence of nano- YAG:Ce and yellow light from Poly[2-methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) polymer. The hybrid nanocomposite-based WLEDs exhibited broad band emission spectra from blue light to red wavelengths and provided the white light with a CIE-1931 coordinate of x = , y = and a colour rendering index Ra = . The obtained results suggest a potential application of nanocomposite based WLEDs in efficient solid-state lighting. I. INTRODUCTION It is known that the solid-state lighting (SSL) is based on lighting from light emitting diode (LED) rather than conventional incandescent and fluorescent lights. Since SSL produces visible light while giving off less heat and reducing energy loss, it has potential applications in both the life and the lighting industrial technology. This technology holds promise for lower energy consumption and reduced maintenance [1, 2]. There are three methods to generate white light by semiconductor LED such as Red + Green + Blue LED, UV LED + RGB phosphor and Blue LED + Yellow phosphor (Fig. 1). Each method has own advantages and disadvantages [2-7]. By the fist method one can make white light by combining
