After two decades of research, organic light-emitting diodes (OLEDs) and semiconductor quantum dots (QDs) have emerged as notable players in the color-display industry. These materials offer superior display contrast, good electrical efficiency, and thin device profile, which are valuable for smart-phones and other electronic display applications. However, their complex synthesis, coupled with expensive vacuum-based thermal evaporation of organics, contribute to high manufacturing costs. In 2014, we discovered a new perovskite-based light-emitting diode (Nature Nanotechnology 2014, 9, 687), which possesses the highly-valued properties of easy electronic-bandgap tuning, narrow spectral line-width and facile solution-processed fabrication. Our current research aims to build on our earlier success to develop high-performance perovskite-based LEDs that can meet the cost, efficiency and the reliability targets that are necessary for successful commercial application. Crucially, our research seeks to bridge the fundamental scientific understanding of perovskite semiconductors with the applications-driven development of high-performance devices. Our research program consist of a combination of (i) material development, (ii) device engineering and (iii) fundamental optical and electrical investigations. This research will deliver important innovations towards a fledging perovskite semiconductor technology that has a high potential in penetrating the color-display industry with its low cost and high performance.

Colloidal quantum dots that emit in the near-infrared (NIR) is a useful class of materials for optical communication, on-chip opto-electronics, covert illumination and bio-imaging applications. Our group develops novel III-V semiconducting quantum dots using new continuous injection synthesis methods. In particular, we have engineered high-efficiency giant-shell quantum dots with an emission wavelength of ~850 nm to match the photo-responsive region of silicon detectors, and employed these dots in NIR light-emitting diodes (Advanced Functional Materials 2019, 1906483). The NIR-emitting quantum dots are also useful in bio-imaging applications due to the weaker absorption and scattering of longer-wavelength photons by biological tissues. This research could open up new opportunities in wearable medical device or covert sensing technologies, where non-invasive NIR light could be employed to track activities and health conditions.