遅延・二色発光を示す異性体臭化インジウム単結晶を開発～将来の発光デバイスやディスプレイへの応用に期待～

2026-02-19 北海道大学,熊本大学

緑色及び黄色発光を示し、異性体のような関係を持つ有機-無機ハイブリッド型臭化インジウム結晶（(C₁₀H₂₂N₂)₄In₄Br₂₀）の模式図

＜関連情報＞

• https://www.hokudai.ac.jp/news/2026/02/vasudevan-pillai-biju.html
• https://www.hokudai.ac.jp/news/pdf/260219_pr2.pdf

遅延発光及び二色発光を示す異性体の有機-無機臭化インジウム単結晶 Isomeric organic–inorganic indium bromide single crystals with delayed and dual colour emission

Haichao Zhou,Kiyonori Takahashi,Takuya Okamoto,Jianguo Pan and  Vasudevanpillai Biju
Materials Horizons  Published:29 Jan 2026
DOI:https://doi.org/10.1039/D5MH02322J

Abstract

Hybrid metal halides attract significant attention in materials science, chemistry, and photonics due to their attractive structural, electronic, and optical properties. However, zero-dimensional (0D) hybrid indium halides are still in their infancy. We report the first isomeric 0D indium halide single crystals showing green and delayed yellow emissions. Single-crystal X-ray structures reveal that these emissions originate from crystals with the molecular formula (C₁₀H₂₂N₂)₄In₄Br₂₀, consisting of organic ligands, InBr₆ octahedra, and InBr₄ tetrahedra. While both crystals carry eight corner-sharing and two face-sharing InBr₆ octahedra, the four face-sharing InBr₄ tetrahedra in the green-emitting isomer and two inner InBr₄ tetrahedra in the yellow-emitting isomer mark the crystal isomerism, leading to distinct optical properties. The green-emitting crystals exhibit short excitonic lifetimes, whereas the radiative recombination in the yellow-emitting crystals is delayed by several hundred nanoseconds and redshifted, indicating a self-trapped exciton behaviour with a large Huang–Rhys factor and high activation energy. The structural and optical properties of the isomeric single crystals offer insights into the importance of developing 0D metal halides with multi-colour and delayed emission for sensors, LEDs, and displays.