Phosphor‐in‐glass thick film formation with low sintering temperature phosphosilicate glass for robust white LED

Abstract Phosphor‐in‐glass (PiG) thick film was fabricated on a borosilicate glass substrate using a conventional screen printing method and employing phosphosilicate glass to allow low‐temperature sintering. The vehicle content and sintering temperature were optimized to form a thick film with a thickness of ~50 μm. Commercial yellow (Y 3 Al 5 O 12 :Ce 3+ ) and red (CaAlSiN 3 :Eu 2+ ) phosphors were successfully incorporated within the glass matrix and then sintered at 550°C. Color‐tunable white LED s were achieved using the PiG thick films as a color converter by varying the glass to phosphor (GtP) ratio. The high luminous efficacy of up to ~120 lm/W and high color rendering index of up to 89 in combination with the thermal quenching property prove the practical feasibility of the PiG thick films for high‐power/high‐brightness LED applications.