Stark sublevels of Er3+–Yb3+ codoped Gd2(WO4)3 phosphor for enhancing the sensitivity of a luminescent thermometer. Issue 62 (15th June 2016)

• Record Type: Journal Article
• Authors: Lu, Hongyu; Meng, Ran; Hao, Haoyue; Bai, Yunfeng; Gao, Yachen; Song, Yinglin; Wang, Yuxiao; Zhang, Xueru
• Is Part Of: RSC advances. Volume 6:Issue 62(2016)
• Page Start: 57667
• Page End: 57671
• Publication Date: 2016-06-15
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra10138k
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Using the FIR technique, the temperature sensing behavior is investigated based on five pairs of thermal coupling levels ( 2 H11/2 / 4 S3/2(2), 2 H11/2 / 4 S3/2, 2 H11/2 / 4 S3/2(1), 4 S3/2(2) / 4 S3/2(1) and 4 F9/2(2) / 4 F9/2(1) ). Abstract : We report a strategy for enhancing the sensitivity of an optical thermometer by utilizing the Stark sublevels. Under 980 nm excitation, the upconversion emission originating from the Stark levels of Er 3+ ( 4 S3/2(2) / 4 S3/2(1) and 4 F9/2 / 4 F9/2(1) ) is observed in a monoclinic phase Gd2 (WO4 )3 :Er 3+ /Yb 3+ phosphor, which is synthesized through the co-precipitation method. The temperature sensing behavior is studied over the range of 296–620 K based on thermal coupling levels 2 H11/2 / 4 S3/2(2), 2 H11/2 / 4 S3/2, 2 H11/2 / 4 S3/2(1), 4 S3/2(2) / 4 S3/2(1) and 4 F9/2(2) / 4 F9/2(1) using fluorescence intensity ratio (FIR) technology. The sensitivity based on Stark sublevels 2 H11/2 / 4 S3/2(2) or 2 H11/2 / 4 S3/2(1) is almost twice more than that based on the traditional 2 H11/2 / 4 S3/2 levels. The obtained maximum sensitivity of the optical thermometer is 16.5 × 10 −3 K −1 at 395 K ( 2 H11/2 / 4 S3/2(2) ). These results suggest that the use of Stark levels is a promising approach for enhancing the sensitivity of optical thermometers.