High quality lead-free perovskites toward white light emitting diodes and X-ray imaging. Issue 43 (21st October 2022)

• Record Type: Journal Article
• Authors: Yan, Shuangpeng; Liu, Sibo; Teng, Zhaowei; Li, Hao; Chen, Weiqing; Zhou, Wei; Qiu, Jianbei; Yu, Xue; Wang, Shuang; Xu, Xuhui
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 43(2022)
• Page Start: 16294
• Page End: 16300
• Publication Date: 2022-10-21
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc03823d
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The luminescence mechanism of the vacancy ordered lead-free perovskite synthesized using a hydrothermal method is fully discussed. Finally, this material is applied to white light emitting diodes and X-ray imaging. Abstract : Lead-free metal halide perovskites have become emerging candidates for white light emitting diodes and X-ray imaging, and exploration of the corresponding down-conversion phosphors and scintillators based on perovskite structures with a high-performance for advanced devices is ongoing. Here, we synthesized Cs2 HfCl6 : Te 4+ crystals with a yellow emission at 557 nm and a wide full width at half maximum around 104 nm, which is attributed to the transition from the triplet state to the ground state ( 3 P1 → 1 S0 ) of Te 4+ ions. Moreover, the energy transfer process from the self-trapped exciton of Cs2 HfCl6 to Te 4+ ions is demonstrated. Accordingly, the white light emitting diodes show a color rendering index of 61.8, which was manufactured by employing the Cs2 HfCl6 :3% Te 4+ crystals with a photoluminescence quantum yield of 74.2%. Furthermore, the Cs2 HfCl6 : Te 4+ crystals exhibit a fascinating steady-state X-ray light yield reaching 76, 194 photons MeV −1, a low detection limit of 36.2 nGy s −1 and a high spatial resolution of 11 lp mm −1 . Hence, this study offers new insight for the development of lead-free metal halide perovskites and promotes their versatile application in white light emitting diodes and X-ray imaging.