Dibenzothiophene sulfone-based n-type emissive organic semiconductor†

Abstract

Developing high-mobility emissive organic semiconductors (OSCs) is crucial for organic light-emitting transistors (OLETs), which belong to a type of the smallest integrated optoelectronic devices, with great potential in next-generation display technologies. Although p-type high-mobility emissive OSCs have achieved considerable progress, n-type OSC materials have rarely been reported. Herein, we designed and synthesized an n-type dibenzothiophene sulfone-based emissive organic semiconductor of DPIDBSO with photoluminescence quantum yields (PLQYs) of 30% in the solid state. Interestingly, it was found that in the DPIDBSO crystal, the growth direction was along the short axis of the molecule rather than along the π–π stacking direction owing to multiple weak hydrogen bonds and the presence of a crystal growth dead zone. Leveraging this “special” crystal, DPIDBSO demonstrated typical n-type transport with an electron mobility of 0.17 cm² V⁻¹ s⁻¹. More importantly, DPIDBSO-based devices with only Ag electrodes showed obvious electroluminescence with an immobile emission zone in the unipolar mode. This work provides deep insights into the development of n-type OSCs with tunable optoelectronic properties through the control of the aggregation state towards high-performance OLETs.