Phosphor-Conversion White Light Emitting Diode Using InGaN Near-Ultraviolet Chip

Abstract

We fabricated a phosphor-conversion white light emitting diode (LED) using an InGaN chip that emits 400 nm near-ultraviolet (n-UV) light and phosphors that emit in the blue and yellow region. When the white LED was operated at a forward-bias current of 20 mA at room temperature (RT), the color temperature (Tcp), average color rendering (Ra), operating voltage (Vf) and luminous efficacy (ηL) were estimated to be 5800 K, 85.3, 3.2 V, and 26.1 lm/W, respectively. With increasing forward-bias current, the luminous flux increased almost linearly and was estimated to be 5.0 lm at 60 mA. The Commission Internationale de l'Eclairage (CIE) chromaticity coordinates obtained from the measured spectra remained almost constant during the forward-bias current increase from 0.5 mA to 60 mA.