TIME-RESOLVED EFFECTS OF AN ELECTRIC-FIELD IN RECOMBINATION FLUORESCENCE

Quenching of the recombination fluorescence by an external electric fi eld was investigated in hexane, tetradecane, and squalane solutions of p-terphenyl and 2.5-diphenyloxazole irradiated with X-rays. The kinet ics of the recombination fluorescence I(E, t) was measured in a nanose cond time scale and the quenching-efficiency curves Q(E, t) = 1 - I(E, t)/I(0, t) were plotted. The dependence Q(E, t) was shown to have the specific character Q(E, t) = f(pt), where p = AE(2)D/r(c)(2). Here A is a constant dependent on the initial-distance distribution function of the charges, E is the electric field strength, D is a mutual diffus ion coefficient of the recombining ions, and r(c), is the Onsager radi us. The quadratic dependence of the parameter p on the electric field strength was shown to be a consequence of the diffusion-controlled rea ction of ion recombination.