A Focus on our PhD Students – Dr Junho Jang

I am currently a Post-Doctoral researcher in the group of Professor Byeong-Soo Bae at the Korea Advanced Institute of Science and Technology (KAIST, Republic of Korea), where my research focusses on the development of composite materials based on sol-gel derived siloxane hybrid materials for displays and optoelectronics. Prior to this, during my M.S. degree, I developed flexible and robust hybrid transparent conducting electrode (TCE) films composed of electroplated metal grid and surface-embedded metal nanowires in glass-fabric reinforced plastic (GFRH). This hybrid TCE film exhibited excellent thermal, chemical and mechanical stability. By using this robust hybrid electrode, I demonstrated flexible optoelectronics such as organic light-emitting diodes (OLED), organic (and perovskite) solar cells, touch screen panels, etc. Subsequently, during my PhD study, I developed siloxane-encapsulated luminescent nanocrystals for highly stable wavelength converting materials. In-situ sol-gel synthesized siloxane-encapsulated nanocrystals of rareearth-doped nanocrystals (upconversion nanocrystals), semiconducting nanocrystals (quantum dots), and metal halide perovskite nanocrystals showed extremely stable photoluminescence in harsh environments (such as high temperature and high humidity, various polar chemicals, and continuous light irradiation) without any protecting layers and ligand exchange process. These stable wavelength converting materials can be applied to infrared sensors and displays. I was honoured to receive the 2020 ISGS PhD Thesis award (3 rd place) for my dissertation results.

After receiving my PhD degree, my current post-doctoral research has been focused on the further development of solgel derived siloxane-hybrid-based stable wavelength converting materials for full-colour micro LEDs or quantum nanoemitting diodes (QNEDs). This work involves collaboration with other research groups in universities and high-technology companies. This combination can lead to excellent – and often unexpected – outcomes, and my research objective is to continue developing productive collaborations with experts in various fields to create new science and technology.

Finally, I would like to acknowledge Professor Byeong-Soo Bae who is my advisor, the members of our research group (Laboratory of Optical Materials and Coatings in KAIST), and other collaborators in various Institutes for supporting me during my dissertation and for their ongoing collaborations which continue to generate excellent and exciting outcomes.