White LED featuring remote phosphor with poly(vinylidene fluoride-co-hexafluoropropylene)

A flexible remote phosphor (RP) sheet based on thermally stable polymer, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), is prepared for a warm white light-emitting diode (WLED) by adopting a simple route. The highly thermal stability of the PVDF-HFP is confirmed by means of thermogravimetric analysis. The luminous efficacy (65.7±2.9 lm/W) and the chromaticity coordinates (0.4578, 0.4107) of the WLED applying PVDF-HFP-based RP sheet remain steady under continuity of current injection of 350 mA for a long-term duration of 1000 h. A better uniformity in correlated color temperature (CCT) of such WLED is obtained, with reference to the CCT uniformity of a WLED made of sapphire-based RP.