Congratulations to UBC Chemistry alumnus Ryoga Hojo on being named the first-ever recipient of the Chris Orvig Doctoral Prize in Chemistry! Hojo completed his PhD in the Hudson Group, graduating in August 2025.
This annual award recognizes the best PhD thesis in the Department of Chemistry. Hojo’s thesis is titled “Thermally Activated Delayed Fluorescence: From Rational Design to Applications in Photocatalysis”.
Thesis Synopsis
Organic light-emitting materials are central to modern technologies, including displays, bioimaging, and light-driven chemical processes. Many of the most efficient systems for these applications traditionally rely on precious metals such as iridium or platinum, which are costly, scarce, and environmentally burdensome. Thermally activated delayed fluorescence (TADF) has emerged as a new generation of organic emitters that delivers high performance using only organic elements, offering a sustainable and metal-free alternative.
This thesis focuses on understanding how the molecular structure of TADF emitters controls their interaction with light. TADF materials can harvest excited states that would otherwise be lost as heat, enabling efficient light emission and long-lived excited states without the use of heavy metals. By systematically modifying molecular frameworks and examining their optical behavior, this work establishes clear relationships between molecular design and properties such as emission color, photoluminescence efficiency, and excited-state lifetime. These insights provide practical guidelines for designing robust and tunable organic emitters for both display technologies and applications in photocatalysis.
Building on these design principles, the thesis demonstrates how the long-lived excited states of TADF molecules can be harnessed for organic photocatalysis. Metal-free TADF emitters enable state-of-the-art light-driven chemical transformations and controlled polymerization processes under mild conditions, highlighting their potential to replace precious-metal photocatalysts in a range of chemical reactions. These concepts are further extended to photo-responsive reagents that allow for the facile modification of surfaces and nanoparticles. Overall, this work advances sustainable strategies for using organic emitters to harness light for chemical reactions and functional materials, reducing reliance on scarce precious-metal resources.