Analysis of Effect of Singlet-Triplet Annihilation in a Low-Threshold Optically Pumped Organic Semiconductor Laser

摘要

We investigate the impact of optical excitation in a low-threshold organic semiconductor vertical-cavity surface-emitting laser (OVCSEL) to achieve lasing. We study the threshold behavior and the dynamics of the optimized OVCSEL structure when pumped by both picosecond and nanosecond pulses. The boundary between pulsed and continuous wave lasing is analyzed for the study of annihilation quenching losses in the proposed OVCSEL. Results from numerical simulation show that, for the picosecond pulses excitation case, the singlet-triplet annihilation is not effective and a lasing threshold of about 0.75 mu J cm(-2) can be obtained. We show that for the nanosecond pulses pumping case, triplet excitons largely quench singlet excitons and lasing is sustained for a short time following turn-on of the pump.