YNbO4:Yb3+/Er3+ is synthesized using a solid-state reaction process with a LiCl flux. The effects of the Er/(Yb+Er) ratios (REr) on the up-conversion (UC) and down-conversion (DC) spectra are investigated. The XRD data confirm that the Yb3+ and Er3+ ions are fully substituted for the Y3+ sites. The UC emission spectra activated by 980 nm consists of green and red emission bands, which originate from the Er3+ ions through an energy transfer (ET) process from Yb3+ to Er3+. The UC emission intensity depends on the REr value, and the findings demonstrate that REr ≤ 0.14 is suitable for an effective UC process. The DC emission spectra under 269 nm radiation of the synthesized powders exhibits not only a strong blue emission assigned to the [NbO4]3− niobates, but also green peaks that originate from the Er3+ ions through an ET process between [NbO4]3− and Er3+.

• 박정혜(경기대학교 공과대학 신소재공학과, 루멘스 주식회사) | Jung Hye Park
• 안원식(경기대학교 공과대학 신소재공학과) | Wonsik Ahn
• 이은영(경기대학교 공과대학 신소재공학과, 한국전자부품연구원) | Eun Young Lee
• 김영진(경기대학교 공과대학 신소재공학과) | Young Jin Kim Corresponding author