Lifetime of Excited States Producing Charge Carriers in Molten Aromatics

Excitation of the lowest triplet state in molten naphthalene, pyrene, and anthracene gives rise to a photocurrent. The lifetime of the excited states responsible for charge-carrier formation is 250±50 msec for naphthalene, 40±10 msec for pyrene, and approximately 10 msec for anthracene. It is determined (i) from the time response of the photocurrent after starting and shutting off illumination, and (ii) from the time dependence of the photocurrent peak which is observed if the external voltage is applied with a certain delay time after shutting off illumination.