High colour rendering index and warm emission of conventional white-LED capped with metal-phthalocyanine/CdSe nanocomposites

Abstract

Improving the colour rendering indices and chromatic stability of conventional phosphor-converted white light-emitting diodes (WLEDs) is crucial to use them as exclusive replacements for traditional light sources. In this work, we attempt to improve these parameters by depositing a free-standing nanocomposite film of metal phthalocyanine (FePc/NiPc) and CdSe QDs onto the conventional WLEDs.Interestingly, capping WLEDs with organic/inorganic FePc/CdSe or NiPc/CdSe nanocomposites significantly improves their colour rendering index (CRI); R9 has increased from 9 to > 50, while Ra has increased from 70 to > 85. They also slightly shift the colour coordinates of WLEDs to the yellow-red range and convert WLED emissions from cool white to warm white. We also demonstrate the excellent colour stability of all WLEDs covered with MPc/QDs when the operating current and operating time are increased. These organic/inorganic FePc/CdSe or NiPc/CdSe nanocomposites are promising materials for improving the performance of conventional WLEDs.