Two dimethylamino-carbaldehyde derivatives with differentπ-bridge lengths were prepared,and their transient optical properties and photophysical mechanisms were investigated by transient absorption spectroscopy and Z...Two dimethylamino-carbaldehyde derivatives with differentπ-bridge lengths were prepared,and their transient optical properties and photophysical mechanisms were investigated by transient absorption spectroscopy and Z-scan measurements.Owing to the difference in molecular structures,the two compounds exhibit different populations of locally excited states and,therefore,they also produce different transient absorption spectra.After photoexcitation,both molecular materials exhibit a wide excited state absorption band from 450 nm to 1000 nm.Meanwhile,the excited state lifetimes are dramatically different,2 ns and 100 ps,for the two molecules.A figure of merit greater than 2 at the wavelength of1000 nm is obtained.The results show that modulating the population of the locally excited states in this type of molecule can be a promising approach for obtaining optical switching and solar cell materials.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1630103 and 11704273)Natural Science Foundation of Jiangsu Province,China(Grant No.BK20170375)Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,China(Grant No.17KJB140021)
文摘Two dimethylamino-carbaldehyde derivatives with differentπ-bridge lengths were prepared,and their transient optical properties and photophysical mechanisms were investigated by transient absorption spectroscopy and Z-scan measurements.Owing to the difference in molecular structures,the two compounds exhibit different populations of locally excited states and,therefore,they also produce different transient absorption spectra.After photoexcitation,both molecular materials exhibit a wide excited state absorption band from 450 nm to 1000 nm.Meanwhile,the excited state lifetimes are dramatically different,2 ns and 100 ps,for the two molecules.A figure of merit greater than 2 at the wavelength of1000 nm is obtained.The results show that modulating the population of the locally excited states in this type of molecule can be a promising approach for obtaining optical switching and solar cell materials.
