광역동 치료와 유기발광소자 발광층에 쓰이는 적색-근적외선 발광체 합성과 연구

Abstract

Recently, development of organic near infrared emitters has drawn attention since it has various application such as night-vision display, organic light emitting diodes, photodynamic therapy, photobiomodulation therapy and sensors. However, synthesis of deep-red and NIR luminophore is challenging since they suffer from high probability of nonradiative transition process by energy gap law and concentration quenching effect. Herein, I present novel deep-red and NIR luminophores - thermally activated delayed fluorescence organic sensitizer and iridium complexes and their application on organic light emitting diodes or photodynamic therapy sensitizer. In particular, I focus on the design strategies that may increase luminescence efficiency, while pushing the emission band more deeply in the NIR region. Various iridium complexes and small organic molecules were synthesized and characterized with UV-visible spectroscopy, photoluminescence spectroscopy, X-ray crystal analysis and time-resolved photoluminescence to identify correlation between molecular structure, quantum yield, aggregation induced emission effect and band gap tuning. This study suggests that further progress can be achieved in the future, with enhanced efficiency, stability and cheaper NIR luminophores.