Indication of current-injection lasing from an organic semiconductor - Sandanayaka, Atula S. D.; Matsushima, Toshinori; Bencheikh, Fatima; Terakawa, Shinobu; Potscavage, William J.; Qin, Chuanjiang; Fujihara, Takashi; Goushi, Kenichi; Ribierre, Jean-Charles; Adachi, Chihaya (Applied physics express, 2019)