Indication of current-injection lasing from an organic semiconductor

In this study, we investigate the lasing properties of 4,4'-bis[(N-carbazole) styryl] biphenyl thin films under electrical pumping. The electroluminescent devices incorporate a mixed-order distributed feedback SiO2 grating into an organic light-emitting diode structure and emit blue lasing. The results provide an indication of lasing by direct injection of current into an organic thin film through selection of a high-gain organic semiconductor showing clear separation of the lasing wavelength from significant triplet and polaron absorption and design of a proper feedback structure with low losses at high current densities. This study represents an important advance toward a future organic laser diode technology. (C) 2019 The Japan Society of Applied Physics