Preparing and testing the reliability of long-afterglow SrAl2O4:Eu2+, Dy3+ phosphor flexible films for temperature sensing. Issue 19 (20th March 2020)

• Record Type: Journal Article
• Authors: Wang, Li; Shang, Zhaojiang; Shi, Mingming; Cao, Peiyuan; Yang, Bobo; Zou, Jun
• Is Part Of: RSC advances. Volume 10:Issue 19(2020)
• Page Start: 11418
• Page End: 11425
• Publication Date: 2020-03-20
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0ra00628a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Owing to its stability and environment-friendly properties, the SrAl2 O4 :Eu 2+, Dy 3+ (SAOED) phosphor has attracted major scientific interest. Abstract : Owing to its stability and environment-friendly properties, the SrAl2 O4 :Eu 2+, Dy 3+ (SAOED) phosphor has attracted major scientific interest. With various applications, such as in emergency signage, luminous paints, and traffic signs, it can have a considerable impact on everyday activities. However, SrAl2 O4 easily undergoes hydrolysis in the presence of atmospheric moisture. To remedy this, we prepared a phosphor film by spin coating to improve its water resistance. The SAOED was coated with epoxy resin glue without destroying the SrAl2 O4 crystals. A series of reliability tests were conducted on the phosphor films and bare phosphors: high-temperature and high-humidity (HT) tests, thermal-cycling (TC) tests, and xenon lamp aging (XLG) tests. Then, the crystal phase, surface morphology, photoluminescence (PL), afterglow decay, and temperature-dependent PL were analyzed. The X-ray diffraction patterns show that the hydrolysis reaction of SAOED occurred easily, with the SrAl2 O4 phase becoming the Sr3 Al2 (OH)12 phase and SrAl3 O5 (OH) generated under HT tests. The PL intensity of the thin film of SAOED decreased 57.2%, 79.3%, and 98.8% after HT tests, XLG tests for 168 h, and TC tests with 10 repetitions from 233 K to 423 K, respectively. Moreover, the afterglow decay time of the SAOED phosphor film was longer than that of bare phosphors. The developed flexible films are excellent candidates for temperature sensing because they exhibit temperature-dependent PL intensity and are highly sensitive to surrounding temperature variation 300–420 K. Thus, SAOED films with stable luminescent signals can be used in energy-efficient, long-lasting temperature-sensing devices, which, apart from being environment-friendly, play a role in improving public safety infrastructure.