High-Performance Organic Laser Semiconductor Enabling Efficient Light-Emitting Transistors and Low-Threshold Microcavity Lasers

• Published in: Nano letters Vol. 22; no. 14; pp. 5803 - 5809
• Main Authors: Yin, Fan, De, Jianbo, Liu, Meihui, Huang, Han, Geng, Hua, Yao, Jiannian, Liao, Qing, Fu, Hongbing
• Format: Journal Article
• Language: English
• Published: American Chemical Society 27.07.2022
• Subjects: H-aggregation; single-crystal microplates; organic light-emitting transistors; herringbone packing; organic lasers
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.2c01345

An organic light-emitting transistor (OLET) is a candidate device architecture for developing electrically pumped organic solid-state lasers, but it remains a critical challenge because of the lack of organic semiconductors that simultaneously possess a high solid-state emission efficiency (Φs), a high and balanced ambipolar mobility (μh,e), and a large stimulated emission cross-section. Here, we designed a molecule of 4,4′-bis­(2-dibenzothiophenyl-vinyl)-biphenyl (DBTVB) and prepared its ultrathin single-crystal microplates with herringbone packing arrangements, which achieve balanced mobilities of μh = 3.55 ± 0.5 and μe = 2.37 ± 0.5 cm2 V–1 s–1, a high Φs of 85 ± 3%, and striking low-threshold laser characteristics. Theoretical and experimental investigations reveal that a strong electronic coupling and a small reorganization energy ensure efficient charge transport; meanwhile, the exciton-vibration effect and negligible π–π orbital overlap give rise to highly emissive H-aggregates and facilitate laser emission. Furthermore, OLET-based DBTVB crystals offer an internal quantum efficiency approaching 100% and a record-high electroluminescence external quantum efficiency of 4.03%.