Improvement Of The Quasi-Continuous-Wave Lasing Properties In Organic Semiconductor Lasers Using Oxygen As Triplet Quencher

We demonstrate quasi-continuous-wave lasing in solvent-free liquid organic semiconductor distributed feedback lasers based on a blend containing a liquid 9-(2-ethylhexyl)carbazole host doped with a blue-emitting heptafluorene derivative. The liquid gain medium is bubbled with either oxygen or nitrogen in order to investigate the role of a triplet quencher such as molecular oxygen on the quasi-continuous-wave lasing properties of organic semiconductor lasers. The oxygenated laser device exhibits a low threshold of 2 mu J cm(-2), which is lower than that measured in the nitrogenated device and is independent of the repetition rate in a range between 0.01 and 4 MHz. Published by AIP Publishing.