Highly thermal-stable warm w-LED based on Ce:YAG PiG stacked with a red phosphor layer

• Chromaticity tuning in PiG is achieved by stacking a red phosphor layer on it.
• The PiG-based warm w-LED yields an admirable LE of 93.9 lm/W.
• Stacking order and red phosphor amount greatly influence the w-LED performance.
• The developed material shows great superiority in thermal resistivity.

We realize a facile chromaticity tuning for the Y3Al5O12:Ce3+ phosphor-in-glass (PiG) based w-LED, with the aid of a CaAlSiN3:Eu2+ red phosphor layer in a remote-type stacking configuration. It was experimentally demonstrated that both the stacking order and the relative amount of red phosphor influence the electroluminescent performance of the constructed w-LED significantly, and the optimized warm w-LED exhibits admirable performance with a luminous efficacy of 93.9 lm/W, a correlated color temperature of 3346 K, a color rendering index of 77.3, and a color shift deviating from Planckian locus in Duv of 0.0034. Significantly, the red phosphor layer stacked PiG based warm w-LED presents an excellent heat resistance, endowing the device with long life-time, which may serve as a promising robust high-power indoor lighting source.