QuMat related seminar

2024-02-05, 11:00 – Ornsteinlaboratorium 2.60 Line it up: Synthesizing and assembling colloidal nanoplatelets for light emission applications Speaker: Yunan Gao – School of Physics, Peking University Host: Hai Wang

Abstract:

The 2023 Nobel Prize in Chemistry has been awarded to three scientists including M. Bawendi, L. Brus and A. Yekimov for their discovery and synthesis efforts in quantum dots. One critical reason underlying the prize lies in the fact that quantum dots have shown great potential in next-generation high-definition display and lighting and lasing applications. Currently, further improvements in external quantum efficiency (EQE) of Colloidal quantum dot light-emitting diodes (QLEDs), which typically exploit isotropic nanocrystals, have been limited by the external coupling factor. The emergence of colloidal two-dimensional nanoplatelets (NPL) with anisotropic shapes offers the opportunity to further improve EQE by controlling their orientation, i.e., the direction of the emitting transition dipoles to allow more light to exit the device. Dr. Yunan Gao will present their recent work on how to achieve high EQE nanoplatelets-based LEDs, systemically covering from synthesis, self-assembly, to the final LED devices.

Yunan Gao has been an Assistant Professor at the School of Physics, Peking University, China, since 2017. He conducted his PhD studies at Delft University of Technology, Netherlands from 2008-2012. He subsequently performed postdoctoral research at the Institute of Physics (Chinese Academy of Sciences), and the Massachusetts Institute of Technology (MIT) before joining Peking University.

Reference
1. ​Highly Efficient Light-Emitting Diodes Based on Self-Assembled Colloidal Quantum Wells. Y. Zhu et.al, Adv. Mater. 2023, 35, 2305382.
2. Controlled Core/Crown Growth Enables Blue-Emitting Colloidal Nanoplatelets with Efficient and Pure Photoluminescence. A. Hu et.al, Small 2022, 18, 2204120.
3. CdSe/CdSeS Nanoplatelet Light-Emitting Diodes with Ultrapure Green Color and High External Quantum Efficiency, P. Bai et.al, J. Phys. Chem. Lett. 2022 13 (39), 9051-9057.
4. Green CdSe/CdSeS Core/Alloyed-Crown Nanoplatelets Achieve Unity Photoluminescence Quantum Yield over a Broad Emission Range, A. Hu et.al, Adv. Optical Mater. 2022, 2200469.
5. Printing and In Situ Assembly of CdSe/CdS Nanoplatelets as Uniform Films with Unity In-Plane Transition Dipole Moment, P. Bai et.al, J. Phys. Chem. Lett. 2020, 11, 11, 4524.
6. CdSe Nanoplatelet Films with Controlled Orientation of their Transition Dipole Moment, Y. Gao et.al, Nano Lett. 2017, 17, 6, 3837.

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