Review—A Review on Phosphor in Glass as a High Power LED Color Converter

Phosphor-in-glass (PiG) is a mixture of a transparent glass and ceramic phosphors and has been recently commercialized for its various advantages as an inorganic color converter for white light emitting diodes (wLEDs). Since the successful demonstration of the wLED and its improved stability over the conventional phosphors in silicon or organic resins, extensive studies have been reported to improve its color conversion and resultant LED properties, such as luminescence efficacy, chromaticity, correlated color temperature and color gamut, as well as its long term stability. Various attempts have also been made to fabricate a PiG structure and to extend its applications. This study reviews the recent progress of PiG and discusses various approaches that have been proposed to overcome the technical issues related to PiG.