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Il Nuovo Cimento D

, Volume 12, Issue 2, pp 233–243 | Cite as

Fluorescence lifetimes in the biphenyl-tetracyanobenzene crystal doped with TCNQ

  • G. Agostini
  • G. Giacometti
  • A. Toffoletti
  • L. Pasimeni
Article

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.

PACS 78.55

Photoluminescence 

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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Copyright information

© Società Italiana di Fisica 1990

Authors and Affiliations

  • G. Agostini
    • 1
  • G. Giacometti
    • 1
  • A. Toffoletti
    • 1
  • L. Pasimeni
    • 2
  1. 1.Dipartimento di Chimica Fisica dell’UniversitàPadovaItalia
  2. 2.Dipartimento di Chimica Inorganica e Struttura Molecolare dell’UniversitàMessinaItalia

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