Summary
Transient optical emission spectra of biphenyl-1,2,4,5-tetracyanobenzene crystal doped with TCNQ have been investigated in the (77÷300) K temperature range. Host prompt fluorescence lifetimes have been measured by cross-correlation phase fluorometry. The decay signal is fitted by a biexponential function whose coefficients are strongly dependent on temperature. A thermal activation energy of 300 cm−1 for the diffusion of singlet exciton has been determined.
Riassunto
È stata esaminata l’emissione ottica, risolta nel tempo, del cristallo di bifenile-1,2,4,5-tetracianobenzene drogato con TCNQ, nell’intervallo di temperatura (77÷300) K. Sono stati misurati i tempi di vita della fluorescenza pronta col metodo del ritardo di fase e della demodulazione. Il decadimento della fluorescenza risulta una funzione esponenziale i cui coefficienti dipendono fortemente dalla temperatura. È stata determinata una energia di attivazione termica di 300 cm−1 per la diffusione dell’eccitone di singoletto nel cristallo.
Резюме
В области температур (77÷300) K исследованы переходные оптические спектры излучения кристалла бифенил-1,2,4,5-тетрационобензола с добавками TCNQ. Измерена длительность мгновенной флуоресценции первичного кристалла, используя фазовую флуорометрию. Затухающий сигнал описывается биэкспоненциальной функцией с коэффициентами, сильно зависящими от температуры. Определена энергия тепловой активации 300 см−1 для диффузии синглетного экситона.
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This work was supported in part by the Italian National Research Council (CNR) through its Centro di Studio sugli Stati Molecolari Radicalici ed Eccitati.
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Agostini, G., Giacometti, G., Toffoletti, A. et al. Fluorescence lifetimes in the biphenyl-tetracyanobenzene crystal doped with TCNQ. Il Nuovo Cimento D 12, 233–243 (1990). https://doi.org/10.1007/BF02450458
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DOI: https://doi.org/10.1007/BF02450458