A High Performance Deep Blue Organic Laser Gain Material

High performance organic lasers with both good optical lasing property and desirable carrier mobility still remains a big challenge for realizing electrically pumped organic lasing. In this work, we have developed a carbazole-end-capped ladder-type oligo-(p-phenylene) based hybrid oligomer as solution-processable deep blue laser gain media to reach a good balance between optical property and carrier transporting ability, by introducing moderate steric hindrance into the pi-conjugated planar oligo-(p-phenylene) backbone. This material demonstrates excellent laser performance and moderate hole mobility of 1 × 10^–3 cm² V⁻¹ s⁻¹. The 1-D distributed feedback (DFB) laser exhibits very low lasing threshold of 0.6 nJ pulse⁻¹ and high slope efficiency of 5.9 ± 0.3% (50% fill factor). More importantly, the prominent ASE performance maintained at very thin film samples. The amplified spontaneous emission (ASE) threshold remains very low (16 nJ pulse⁻¹) in the 45 nm-thickness film. These results might indicate possibilities for electrically pumped gain materials.