ABSTRACT
Over the past two decades, there has been tremendous progress in discovering organic and nanostructured semiconductors for applications such as LEDs, solar cells, transistors and sensors. Unlike conventional crystalline semiconductors, organic and nanostructured materials are compatible with low-cost, large-area roll-to-roll processing, needing lower energy intensity for device fabrication; at the same time, the electronic and optical properties of the materials can be easily diversified via composition or morphology tuning. In this talk, I will describe how this class of materials enables a new generation of high-efficiency solar cells, wearable medical devices and optical gas sensors. Firstly, I will introduce our recent work on wide band-gap perovskite solar cells and explain how the device efficiency and stability can be improved via multi-scale material modification combining composition tuning, grain engineering and surface passivation. Secondly, I will present the design and application of high-gain organic heterojunction-based phototransistors for noninvasive physiological measurements, such as photoplethysmography and near-infrared spectroscopy. Lastly, I will introduce HgTe quantum dot-based infrared photodetectors for compact optical gas sensing systems.
BIOLOGRAPHY
Ni Zhao is currently an Associate Professor at the Electronics Engineering Department at the Chinese University of Hong Kong. She received her Ph.D degree in Physics from the University of Cambridge (UK) in 2008. From 2008-2010 she worked as a postdoctoral research fellow at the Massachusetts Institute of Technology (USA). Her current research interests include optoelectronic devices, wearable biomedical devices and optical spectroscopy.
