Advent calendar - December 16th - Yun Hai

In the Zernike Institute Advent Calendar, we are presenting 24 short spotlights in December. In these specials, we highlight PhD students, postdocs, support staff and technicians of our research groups and team - providing a glimpse in their typical day at work. In Episode 16 meet Yun Hai, PhD student in the Nanomaterials Chemistry Group under the guidance of Prof. Loredana Protesescu.

I am a PhD student entering the final year of my doctoral journey. I work in the Nanomaterials Chemistry Group under the guidance of Prof. Loredana Protesescu. Our research focuses on developing advanced functional nanomaterials, including perovskites, quantum dots, and metal borides, using colloidal and solid-state synthesis methods. Furthermore, we aim to understand and tailor their surface chemistry to improve their colloidal and optical stability, enabling their application in diverse fields such as optoelectronic devices and catalysis.

My research centers on synthesizing high-quality, monodisperse III-V quantum dots (QDs), such as indium phosphide (InP) and indium antimonide (InSb), using colloidal chemical synthesis. These III-V QDs exhibit strong quantum confinement effects, meaning their bandgaps can be precisely tuned by adjusting their sizes. This fantastic property was recognized with the 2023 Nobel Prize in Chemistry. The bandgap of III-V QDs can be tuned from the visible to the infrared region (450–2000 nm). Such characteristics form the basis for various optoelectronic devices, including QD-based LEDs, solar cells, and photodetectors. Notably, InP-based QDs are already utilized commercially, with Samsung producing InP-based QLED TVs. On the other hand, InSb QDs, which operate in the infrared spectrum, are gaining attention for applications such as telecommunications, autonomous driving, night vision, augmented reality, and in-vivo bioimaging due to their promising infrared properties.

In addition, my research delves into surface chemistry, a critical factor influencing the physical and chemical properties of quantum dots (QDs). I focus on ligand exchange processes, replacing the original organic ligands with inorganic ones and investigating the underlying mechanisms at an atomic level. The resulting III-V QDs, capped with inorganic ligands, exhibit improved conductivity, making them highly suitable for integration into device fabrication.

Beyond conducting experiments in the lab, traveling has been an indispensable and enriching aspect of my journey. I enjoy exploring different countries, immersing myself in diverse cultures, meeting new people, savoring unique cuisines, and marveling at stunning landscapes. These experiences have significantly broadened my horizons and added depth to my life.

See all Advent Calendar items 2024 here!