Generation and recombination of charge carriers in p-terphenyl crystal. Photoionization of singlet exciton

Abstract

With two-color photoionization, by using a nitrogen laser and a dye laser, it is shown that photoionization of singlet excitons in p-terphenyl crystal occurs with a photoionization cross section of (5.2±1.6)×10 -19 cm2 with 590 nm photons (at 5×10 4V/cm). Volume recombination of electrons and holes sets in at higher excitation intensities. The recombination rate constant γeh is found to be (1.3±0.4)×10-6 cm1s -1. The understanding of the transient current pulse shape allows an in situ determination of the penetration depth of the exciting light, with a consequent improvement in the reliability of the constants determined. © 1983 American Institute of Physics.