You are most welcome to a knowledge-sharing seminar presented by Assoc. Prof. (Steve) Cuong Dang at Nanyang Technological University, Singapore. With a friendly atmosphere, you will have a great chance to discuss and communicate with this young scientist for any potential collaborations or research experience.

​

Title:

​

CONTROLING EXCITONS & TRION IN COLLOIDAL NANOMATERIALS for OPTOELECTRONIC DEVICES

 

Abstract: 

Colloidal nanomaterials with appealing emission characteristics of nanostructures, stability of inorganic semiconductors and solution processability have found their way from lab curiosities to consumer electronics in shopping centers. Engineering the light emission properties is always a demand for various applications. In this talk, I present our recent works on excitonic modulation in colloidal nanomaterials for practical optoelectronic applications. Exciton hoping by Förster resonance energy transfer (FRET) in a long chain of well-aligned nanoplatelets is demonstrated to tune emission color on demand for lighting and display applications [1]. We also demonstrate an all-optical approach to control the exciton flow back and forth between the donor-acceptor pair through modulated FRET by stimulated emission [2, 3]. Finally, we reveal that the negative trion (an excessive electron with a single exciton) can be utilized to enhance the excitonic gain performance [4], which is counter intuitive because trions typically reduce the emission efficieny [5]. The trion manipulation is achieved by electrical control in a capacitor device,  making it preferable for practical applications, proposing a possible way to achieve long-sought practical devices: full-color single-material lasers [6, 7].

​

Biography:

Dr. (Steve) Cuong Dang is an Associate Professor at the School of Electrical and Electronic Engineering, Nanyang Technological University (NTU). He received Ph.D. in Physics and M.Sc. in Electrical and Computer Engineering from Brown University, Rhode Island, USA. His bachelor's degree is in Physics from Hanoi University of Science, Vietnam National University. Dr. Dang's research focuses on nanomaterials, nanophotonics and their applications in sensors, photovoltaics, light-emitting diodes and lasers. He is also interested in manipulating and exploiting light through complex media. Advanced signal processing techniques and optical physics knowledge are combined to demonstrate applications in biomedical imaging, non-invasive imaging or focusing through scattering media. His research has been published and highlighted in top international journals, including Nature Nanotechnology, Nature Photonics, Nature Communications, Science Advances, and Advanced Materials. His innovative research has led to the commercialization of colloidal quantum dots in lighting and displays.

References

[1].  J. Yu, M. Sharma, Y. Wang, S. Delikanli, H.D. Baruj, A. Sharma, H.V. Demir, C. Dang, Modulating Emission Properties in a Host–Guest Colloidal Quantum Well Superlattice, Advanced Optical Materials, 10 (2022) 2101756.

[2].  J. Yu, M. Sharma, S. Delikanli, M.D. Birowosuto, H.V. Demir, C. Dang, Mutual Energy Transfer in a Binary Colloidal Quantum Well Complex, The Journal of Physical Chemistry Letters, 10 (2019) 5193-5199.

[3].  J. Yu, M. Sharma, A. Sharma, S. Delikanli, H. Volkan Demir, C. Dang, All-optical control of exciton flow in a colloidal quantum well complex, Light: Science & Applications, 9 (2020) 27.

[4].  J. Yu, S. Shendre, W.-k. Koh, B. Liu, M. Li, S. Hou, C. Hettiarachchi, S. Delikanli, P. Hernández-Martínez, M.D. Birowosuto, H. Wang, T. Sum, H.V. Demir, C. Dang, Electrically control amplified spontaneous emission in colloidal quantum dots, Science Advances, 5 (2019) eaav3140.

[5]. J. Yu, M. Sharma, M. Li, B. Liu, P. L. Hernandez-Martinez, S. Delikanli, A. Sharma, Y. Altintas, C. Hettiarachchi, T. C. Sum, H. V. Demir, C. Dang, “Efficient generation of emissive many-body correlations in copper-doped colloidal quantum wells”, Cell Reports Physical Science 3 (9), (2022) 101049

[6].  J. Yu, C. Dang, Colloidal Metal Chalcogenide Quantum Wells for Laser Applications, Cell Reports Physical Science, 2 (2021) 100308.

[7].  C. Dang, J. Lee, C. Breen, J.S. Steckel, S. Coe-Sullivan, A. Nurmikko, Red, green and blue lasing enabled by single-exciton gain in colloidal quantum dot films, Nat Nanotechnol, 7 (2012) 335-339.

Time: 10:30 CET, 24th March, 2023

Zoom link:  https://lu-se.zoom.us/j/64527653947

Chairmain: Assoc. Prof. Hai Son Nguyen