PhD student, University of Toronto
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Abstract
Novel Solution-processed Materials for Efficient Optoelectronics
To solve the pressing problems caused by climate change and the energy crisis, researchers have focused on renewable energy. More specifically, efficient energy conversion, storage, and utilization are the key components. Solution processed materials have shown great advantages in fabricating flexible and large area electronics with low cost. Colloidal quantum dots (CQDs) and perovskites are two types of solution processed material with extraordinary physical properties, including their ability in the efficient capture of solar energy, and the bright and sharp emission profile. They are recognized as promising candidates for the applications including solar cells, light emitting diodes, etc.
Colloidal quantum dots (CQDs) are known for their tunable luminescence, high quantum efficiency and solution processability, exhibiting great potential in light emission. However, CQD thin films today still suffer a compromise between luminescence efficiency and charge transport, and this leads to unacceptably high power consumption.
Perovskites have been discovered with excellent carrier transport properties, such as low defect density, high mobility and long diffusion length. This presentation will highlight our recent efforts in marrying up these two materials by designing a hetero-epitaxial junction between CQDs and perovskite. The resulting novel solid material–quantum-dot-in-perovskite– shows superb photophysics properties benefiting from the interactions between the quantum dot and perovskite.
The second part of the presentation will focus on a variety of applications of the QDIP in optoelectronics, such as high performance solar cells, light emission diodes, and photodetectors.
Bio
Xiwen graduated with a bachelor degree in Material Physics in 2014, from Fudan University in Shanghai, China. Since 2014, Xiwen start her PhD study at Electrical and Computer Engineering, University of Toronto. In Sargent group at UofT, Xiwen focuses her research topics on nanocrystals, and emerging hybrid organic-inorganic materials for solar energy harvesting, light emitting, and sensing.
Specifically, Xiwen develops a novel material platform named “quantum dots in perovskite solids” and further investigates its photophysics properties. This new hybrid material leads to optoelectronic devices with record-high performance, such as solar cells, LEDs, and photodetectors. Her work has been published in top-tier journals including Nature, Nature Photonics, Nature Communications, Physical Review B, Nano Letters, and Advanced Materials, etc., with citation > 330.
In her free time, Xiwen loves spring board diving, tennis and currently runs a jogging club with over 30 numbers. She is also a volunteer journalist and writer for MRS Bulletin news. She also devotes herself to broadcast and highlight the news of excellent research to wider audience, by founding and maintaining the official social media (WeChat) account of the Sargent Group.