Evoking non-bonding S-π interaction by aryl phosphine sulfide for selectively enhanced electronic property of organic semiconductors

Abstract

Selective tuning of optoelectronic properties of organic semiconductors is one of the most significant challenges in organoelectronics. Herein, on the basis of aryl phosphine sulfide (APS), we show that the electronic performance can be selectively enhanced by evoking the non-bonding S-π interactions between the sulfur atom of APS and π-conjugated carbazole moiety, on account of the large scope 3p lone-pair electrons of S for effective electronic communications. It is indicated that the material properties and device performances are strongly dependent on the beingness of the successfully established intramolecular S-π interaction. Specifically, APS-based DPSSi exhibits excellent solubility and film-forming ability and enhanced carrier transportation and injection abilities at high triplet energy level; and the DPSSi-hosted blue phosphorescent light-emitting diodes (PhOLEDs) show high current efficiency up to 36.6 cd A−1, power efficiency of 30.6 lm W−1, and external quantum efficiency of 20.8%, which are among the best results of blue PhOLEDs reported so far. The semi-conjugation feature of S-π interaction in selectively modulating electronic properties would offer exciting opportunities for settling intrinsic difficulties of organic optoelectronic materials and devices, promoting significantly the development of non-bonding interaction involved organic optoelectronic molecules.