Seoul National Univ. DMSE
Notice
Notice
Manipulating charge, light and spin interaction in organic-inorganic hybrid perovskites

 

| Title | Manipulating charge, light and spin interaction in organic-inorganic hybrid perovskites


| Speaker | Dr. Young-Hoon Kim, Postdoctoral Researcher, Chemistry and Nanoscience Center, National Renewable Energy Laboratory (NREL)

 

* EDUCATION

- Pohang University of Science and Technology (POSTECH), Pohang, Korea
  * Mar. 2014 – Feb. 2016   Ph.D. Materials Science and Engineering (Prof. Tae-Woo Lee)
  * Mar. 2012 – Feb. 2014   M.S. School of Environmental Science and Engineering

                 (Prof. Tae-Woo Lee)
  * Mar. 2008 – Feb. 2012   B.S. Materials Science and Engineering



* PROFESSIONAL EXPERIENCES 

- Apr. 2019 – Present      National Renewable Energy Laboratory (NREL), Golden, U.S.A.
                                 Post-doctoral researcher (Dr. Josheph M. Luther, Dr. Matthew C. Beard)
- Apr. 2018 – May. 2018  University of Valencia, Valencia, Spain
                                 Visiting scholar (Prof. Hendrik (Henk) Bolink)
- Mar. 2017 – Mar. 2019  Seoul National University (SNU), Seoul, Korea
                                 Post-doctoral researcher in BK21 PLUS SNU Materials Division for

                            Educating Creative Global Leaders (Prof. Tae-Woo Lee)
- Sep. 2016 – Mar. 2019  Seoul National University (SNU), Seoul, Korea
                                 Post-doctoral researcher in Research Institute of Advanced Materials

                            (Prof. Tae-Woo Lee)


 

| Date | Wednesday, March 10th, 2021


| Time | 10:00 ~

 

| Venue | 온라인 강의 (https://snu-ac-kr.zoom.us/j/7614877009)

 

| Abstract |


As the technology has advanced and the amount of information has grown, various technologies have focused on the manipulation of charge, light and spin in semiconducting functional materials to process the information more efficiently. However, traditional organic semiconductors have broad spectral emission and weak spin-orbit coupling, which limit their use in delicate information processing. Inorganic semiconductors require the use of external magnetic field to align the spin and show size-dependent emission in quantum dots (QDs), which complicate the process and make these materials difficult to be used in a broader class of applications.


Here we demonstrate the efficient control over charge, light and spin in organic-inorganic hybrid perovskites by using various nanostructure design strategies. First to control the charge and light interaction, we synthesize the colloidal perovskite nanocrystals and design a ligand engineering which increases the radiative recombination. Furthermore, we exploit a novel one dopant alloying strategy to create an entropy-stabilized phase in bulk while simultaneously passivating the under-coordinated surface defects. As a result, we achieve external quantum efficiency of 23.4% in light-emitting diodes (LEDs), which is the highest efficiency yet reported in perovskite LEDs and comparable with those in the state-of-the art organic LEDs and QD LEDs. Second, we demonstrate full control of charge, light and spin by incorporating chiral small molecules within a layered organic-inorganic hybrid framework. These layered chiral perovskites produce spin-polarized current of >80% only upon an applied electric field, which exhibits 2.6% of circularly polarized electroluminescence in spin-LEDs at room temperature. The effects of chiral ligands on colloidal perovskite nanocrystals will be also discussed.

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| Host | Prof. Min Sang Kwon (880-8326)

 

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