Improved color rendering and luminous efficacy in phosphor-converted white light-emitting diodes by use of dual-blue emitting active regions

Abstract

Conventional white-light sources suffer from a fundamental trade-off between color rendering index and the luminous efficacy; increasing one generally comes at the expense of the other. We demonstrate through simulation that dual-wavelength blue-emitting active regions in phosphor-converted white light sources maximize the output luminous flux while significantly increasing the color rendering ability. Our results indicate that such improvements can be achieved over a broad range of correlated color temperatures. (C) 2009 Optical Society of America