Long-lived emission or afterglow is an interesting phenomenon which usually refers to long lasting visible emission after the cease of excitation sources. Owing to its unique properties, fundamental importance, and potential in development of advanced technological applications, it attracts researcher’s interests from different fields. Based on fundamental differences, it can be divided into phosphorescence and persistent luminescence. About the underlying mechanism of these two kinds of emission, it is related to the photophysics of long-lived excited states presented in the systems. More mechanistic insights and rational understanding is needed for designing new afterglow materials and functional applications with desired properties. Thus, exploring the long-lived excited states is c...[ Read more ]

Long-lived emission or afterglow is an interesting phenomenon which usually refers to long lasting visible emission after the cease of excitation sources. Owing to its unique properties, fundamental importance, and potential in development of advanced technological applications, it attracts researcher’s interests from different fields. Based on fundamental differences, it can be divided into phosphorescence and persistent luminescence. About the underlying mechanism of these two kinds of emission, it is related to the photophysics of long-lived excited states presented in the systems. More mechanistic insights and rational understanding is needed for designing new afterglow materials and functional applications with desired properties. Thus, exploring the long-lived excited states is crucial for the research of afterglow material and it can lead to a more comprehensive progress. In this thesis, organic material that exhibit room temperature phosphorescence (RTP) and long-persistent luminescence (LPL) are investigated through photophyscal approaches. Different molecular design and strategies based on monitoring long-lived states have been employed to realize new RTP and LPL systems. This thesis demonstrates the insights by giving rational understanding and novel examples to the research of organic afterglow material.