RPG Seminar – The Upside-Down Molding Approach for Geometrical Parameter Tunable Photonic Perovskite Nanostructures – [Cancelled]
07 May, 2021 (Fri)
11:00 am
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Mr. Nie Lebin
Department of Electrical and Electronic Engineering
The University of Hong Kong


Generally, the periodic photonic nanostructures are realized by some complicated and multi-step fabrication approaches, such as hot embossing and thermoplastic nanoimprint. It is highly desirable to achieve the goal of fabricating devices using simple room-temperature solution processes. This not only can advance the fabrication, but also unlock the potential applications in emerging optoelectronic such as flexible electronics. In this seminar, we demonstrate the novel approach of upside-down molding-based recrystallization and realized the room-temperature solution-processed perovskite photonic resonators with controllable parameters. Fundamentally, the upside-down molding introduces the capillary force to infiltrate perovskite gel into the narrow grooves of the molds. It initiates the stretching force provided by the gravity of soft templates, rather than the conventional downward extrusion force, to tune the thickness of the perovskite waveguide layer integrated to the nanopattern. In the recrystallization process, we propose the room-temperature gaseous anti-solvent process to eliminate the generated gases. By incorporating the nanopatterning, our nanopatterned perovskites not only show an improvement of the crystallinity, but also achieve an enhancement of optical properties including absorption and emission. The first room-temperature solution-processed nanoimprinted perovskite laser based on the distributed feedback resonator is realized with a low threshold of 15.3 μJ/cm2 and a narrow linewidth of 0.52 nm. This work contributes to a new and facile approach to realize photonic perovskite nanostructures, which is adaptable in both regular rigid and flexible substrates for emerging optoelectronic applications.


Zoom Link (during COVID-19 special period):
Meeting ID: 704 424 7859


Biography of the speaker:
Nie Lebin received the B. Eng. degree in Macromolecule Material and Engineering from South China University of Technology in 2016. He is currently working toward Ph.D. degree at The University of Hong Kong. His research interest is the synthesis of perovskites and photoelectric devices.


All are welcome.


Prof. Wallace Choy

Most seminars are open to the general public, free of charge, unless otherwise stated. Registration is not required. Arrangement for car parking facilities on campus please contact us for details.

For enquiries, please contact:
Department of Electrical and Electronic Engineering,
Room 601, Chow Yei Ching Building,
Pokfulam Road, Hong Kong
Tel: (852) 3917 7093
Email: seminar@eee.hku.hk