Date of Defense
2-6-2026 2:00 PM
Location
F1-2007
Document Type
Dissertation Defense
Degree Name
Doctor of Philosophy in Chemistry
College
College of Science
Department
Chemistry
First Advisor
Fathy Hassan
Keywords
metal halides, optoelectronics, luminescent phosphors, anti-counterfeiting
Abstract
Low-dimensional metal halides are gaining popularity in optoelectronic applications owing to their interesting optical properties and structural diversity. In general, low-dimensional metal halides refer to one-dimensional and zero-dimensional structures. The main difference between the two is that one-dimensional structures have chain-like connectivity, whereas zero-dimensional structures consist of isolated units. Their optical properties are mainly determined by the B-site metal ion, which is coordinated to halide ions in trigonal, tetrahedral, or octahedral geometry. In particular, copper (I) and manganese (II) metal halides are emerging as novel materials for solid-state lighting, and anti-counterfeiting applications. The two well-known phases of cesium copper (I) metal halides are CsCu2I3 and Cs3Cu2I5. In this work, we synthesized yellow-emissive CsCu2I3 phosphors and fabricated a yellow LED with an emission peak centered at 580 nm. Meanwhile, blue-emissive Cs3Cu2I5 was used for two applications. Firstly, we encapsulated Cs3Cu2I5 in Eu-oxalate MOF to synthesize Cs3Cu2I5/Eu-MOF composite with wavelength-dependent emission. Secondly, we doped Mn2+ ions into Cs3Cu2I5 to fabrication single component white-LEDs. As for Cs3MnBr5, we employed a water-assisted solvent evaporation method to synthesize phosphors with a high photoluminescence quantum yield (PLQY) of 85.73% narrow green emission. In addition, we investigated the coordination chemistry, optical and electrical properties, and emission mechanisms of these materials.
Included in
Structure-Property Relationship in Low-Dimensional Cesium Metal Halides: Coordination Chemistry, Luminescent Mechanism and Optoelectronics Applications
F1-2007
Low-dimensional metal halides are gaining popularity in optoelectronic applications owing to their interesting optical properties and structural diversity. In general, low-dimensional metal halides refer to one-dimensional and zero-dimensional structures. The main difference between the two is that one-dimensional structures have chain-like connectivity, whereas zero-dimensional structures consist of isolated units. Their optical properties are mainly determined by the B-site metal ion, which is coordinated to halide ions in trigonal, tetrahedral, or octahedral geometry. In particular, copper (I) and manganese (II) metal halides are emerging as novel materials for solid-state lighting, and anti-counterfeiting applications. The two well-known phases of cesium copper (I) metal halides are CsCu2I3 and Cs3Cu2I5. In this work, we synthesized yellow-emissive CsCu2I3 phosphors and fabricated a yellow LED with an emission peak centered at 580 nm. Meanwhile, blue-emissive Cs3Cu2I5 was used for two applications. Firstly, we encapsulated Cs3Cu2I5 in Eu-oxalate MOF to synthesize Cs3Cu2I5/Eu-MOF composite with wavelength-dependent emission. Secondly, we doped Mn2+ ions into Cs3Cu2I5 to fabrication single component white-LEDs. As for Cs3MnBr5, we employed a water-assisted solvent evaporation method to synthesize phosphors with a high photoluminescence quantum yield (PLQY) of 85.73% narrow green emission. In addition, we investigated the coordination chemistry, optical and electrical properties, and emission mechanisms of these materials.