A vivid example of turning waste into treasure: persistent luminescence of Ca2Ga2(Si, Ge)O7:Pr3+, Yb3+ phosphor tailored by band gap engineering. Issue 42 (12th October 2016)

• Record Type: Journal Article
• Authors: Zou, Zehua; Zhou, Hui; Wang, Wenxiang; Zhang, Jiachi; Cao, Cheng; Zhang, Teng; Ci, Zhipeng; Zhao, Zhengyan; Wang, Yuhua
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 42(2016)
• Page Start: 10026
• Page End: 10031
• Publication Date: 2016-10-12
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6tc03453e
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : We exhibit a vivid example of turning waste into treasure for the development of persistent luminescence (PersL) phosphor. Abstract : We exhibit a vivid example of turning waste into treasure for the development of persistent luminescence (PersL) phosphor. Facing the original experimental failure in which the as-synthesized Ca2 Ga2 SiO7 :Pr 3+, Yb 3+ phosphor showed very weak PersL, we did not give up but made a deep analysis. It reveals that the relatively deep depth of traps (0.72 eV) may be the key reason for the weak PersL of Ca2 Ga2 SiO7 :Pr 3+, Yb 3+ phosphor. Accordingly, in order to make the depth of the traps more shallow, a band gap engineering method was applied by the partial substitution of Si 4+ with Ge 4+ ions. Investigation into the optical spectra and the electronic structures indicate that the band gap has been successfully reduced. Correspondingly, the depth of traps becomes shallower, and it is adjusted in an appropriate range (around 0.65 eV) when Si : Ge = 1 : 9. As a consequence, the original "waste" phosphor with very weak PersL is successfully turned into a valuable PersL phosphor: Ca2 Ga2 (Si0.1 Ge0.9 )O7 :Pr 3+, Yb 3+, whose PersL duration time and initial PersL brightness have been increased by 74 times and 52 times, respectively, compared with the original Ca2 Ga2 SiO7 :Pr 3+, Yb 3+ sample.