Instant precipitation of KMgF3:Ni2+ nanocrystals with broad emission (1.3‐2.2 μm) for potential combustion gas sensors. Issue 9 (30th March 2018)

• Record Type: Journal Article
• Authors: Cao, Jiangkun; Guo, Hai; Hu, Fangfang; Li, Liyi; Xu, Shanhui; Peng, Mingying
• Is Part Of: Journal of the American Ceramic Society. Volume 101:Issue 9(2018)
• Page Start: 3890
• Page End: 3899
• Publication Date: 2018-03-30
• Subjects: glass‐ceramics -- luminescence -- nanocomposites; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.15551
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: Optical gas sensors present fundamental and industrial importance considering their broad applications. Challenges remain to obtain new photonic materials with broadband emission covering the absorption spectrum of typical combustion gases. Here, broadband near‐infrared (NIR) photoluminescence (PL) spanning the wide absorption spectrum of typical combustion products is realized through instant precipitation of stable cubic perovskite KMgF3 :Ni 2+ nanocrystals inside an aluminosilicate glass matrix after melt‐quenching. Excited by an 808 nm laser diode, NIR luminescence with a peak centered at ~1624 nm and a bandwidth (FWHM) greater than 315 nm is observed, originating from 3 T2g ( 3 F) → 3 A2g ( 3 F) electronic transition of octahedral coordinated Ni 2+ in KMgF3 GC. Controlled precipitation of these perovskite crystals from a supercooled aluminosilicate melt enables immediate encapsulation and, hence, stabilization in an inorganic glass phase. While the precipitation temperature has only a small effect on crystallite size, it controls the redox state of the melt and the degree of dopant incorporation into the crystalline phase so that PL performance can be optimized. Spontaneous crystallization of perovskite nanocrystals inside glass may offer a new way to stabilize these novel nanocrystals. Moreover, spontaneous crystallization can be attractive in the control of activator partitioning and in the fabrication of composite fiber devices with high transparency and emission gain. In the present case, this offers a potential platform for broadly tunable gain media, for example, for combustion gas sensing.