Harvesting Triplet Excitons in High Mobility Emissive Organic Semiconductor for Efficiency Enhancement of Light‐Emitting Transistors. Issue 13 (13th February 2023)

• Record Type: Journal Article
• Authors: Gao, Can; Shukla, Atul; Gao, Haikuo; Miao, Zhagen; Zhang, Yihan; Wang, Pu; Luo, Guiwen; Zeng, Yi; Wong, Wallace W. H.; Smith, Trevor A.; Lo, Shih‐Chun; Hu, Wenping; Namdas, Ebinazar B.; Dong, Huanli
• Is Part Of: Advanced materials. Volume 35:Issue 13(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-02-13
• Subjects: harvesting triplet excitons -- high efficiency -- high mobility -- organic light‐emitting transistors -- organic semiconductors -- strong emission -- tunable emission colors; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202208389
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Organic light‐emitting transistors (OLETs), a kind of highly integrated and minimized optoelectronic device, demonstrate great potential applications in various fields. The construction of high‐performance OLETs requires the integration of high charge carrier mobility, strong emission, and high triplet exciton utilization efficiency in the active layer. However, it remains a significant long‐term challenge, especially for single component active layer OLETs. Herein, the successful harvesting of triplet excitons in a high mobility emissive molecule, 2, 6‐diphenylanthracene (DPA), through the triplet‐triplet annihilation process is demonstrated. By incorporating a highly emissive guest into the DPA host system, an obvious increase in photoluminescence efficiency along with exciton utilization efficiency results in an obvious enhancement of external quantum efficiency of 7.2 times for OLETs compared to the non‐doped devices. Moreover, well‐tunable multi‐color electroluminescence, especially white emission with Commission Internationale del'Eclairage of (0.31, 0.35), from OLETs is also achieved by modulating the doping concentration with a controlled energy transfer process. This work opens a new avenue for integrating strong emission and efficient exciton utilization in high‐mobility organic semiconductors for high‐performance OLETs and advancing their related functional device applications. Abstract : Triplet excitons in high mobility emissive semiconductor 2, 6‐diphenylanthracene (DPA) are successfully harvested via triplet‐triplet annihilation and further increased by doping a highly emissive guest. The exciton utilization and device efficiency of DPA are significantly improved in organic light‐emitting transistors (OLETs). This concept can be extended to other advanced high mobility emissive organic semiconductors for promoting the development of OLETs and related functional devices.