세미나 김영훈 교수 [한양대, 에너지공학과] - Chirality in Semiconducting Materials for Circularly Polarized Light and Spin-Optoelectronics
- 작성일
첨부파일
일시: 2026년 5월 7일 (목) 오후 5시
장소: 과학관 B133호
초록:
In addition to the significant attention already focused on optoelectronics, which utilize theinterconversion between light and electrons (e.g., photovoltaics and light-emitting diodes),chiral molecules offer additional functionality for semiconducting materials and devices.Firstly, chiral molecules can selectively control the spin angular momentum of light, enablingthe absorption and emission of circularly polarized light. This property makes them highlyapplicable in encrypted optical communication and quantum computing. Secondly, chiralmolecules can polarize charge carriers without requiring an external magnetic field, a phenomenon known as chiral-induced spin selectivity (CISS). Here, we present a strategy toincorporate chiral molecules into optoelectronic systems to control the direction of both lightand charge carriers. To achieve this, we synthesized chiral organic/inorganic metal halideperovskites. In these materials, A-site chiral ammonium ions transfer chirality to inorganicmetal halides through centro-asymmetric interactions. Through the CISS effect, we achieved a spin-injection selectivity of up to 80% and applied this to spin-polarized light-emitting diodes(spin-LEDs). In spin-LEDs, injected spin-polarized holes recombine with electrons of thecorrect spin direction, emitting light with matching polarization. This system achieved 2.6% circularly polarized electroluminescence at room temperature. Furthermore, we demonstratedcircularly polarized light detectors based on chiral perovskites. These materials areanticipated to provide new avenues for advancing next-generation spin-optoelectronics.