Achieving a near-unity quantum yield from yellow emitting metal halide double perovskites toward human-centric warm white LED lighting. Issue 34 (12th August 2022)

• Record Type: Journal Article
• Authors: Xiong, Guangting; Jin, Yahong; Deng, Kaiyuan; Yuan, Lifang; Wu, Haoyi; Ju, Guifang; Chen, Li; Hu, Yihua
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 34(2022)
• Page Start: 12316
• Page End: 12322
• Publication Date: 2022-08-12
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1tc06173a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : A novel strategy in pursuit of "human-centric" lighting for adjusting excitation to match commercial NUV-LED chips by adding Te 4+ ions, producing a zero-blue radiation and showing bright broadband yellow emission with a maximum PLQY of 95.26%. Abstract : The use of LED lighting results in a prolonged exposure to blue radiation, which is harmful to the human eye health. Herein, a new strategy aiming for "human-centric" lighting is demonstrated by doping Te 4+ into Cs2 HfCl6, leading to zero blue radiation through mixing red and green phosphors in a NUV-LED chip. Cs2 HfCl6 :Te yields an efficient bright yellow emission with a high photoluminescence quantum efficiency of 95.26%. Surprisingly, the emission intensity maintains 96% of its initial value even when the post-annealing temperature is as high as 450 °C, demonstrating superior thermal resistance. Moreover, excellent environmental stability is achieved via a silane coupling agent to modify the surface, and the broadband yellow emission intensity remains at 91% of the initial strength after soaking in water for 100 min and hardly changes after 120 h of storage in air. A packaging device using a 395 nm LED chip, Cs2 HfCl6 :0.5%Te, and green and red-emitting phosphors produces warm white light with a high color rendering index, while significantly eliminating blue radiation. These results demonstrate that Cs2 HfCl6 :Te perovskite is a promising phosphor with the capability of advancing human-centric lighting.