Wide-bandgap organic nanocrystals with high mobility and tunable lasing emission

Abstract

Here, a wide-bandgap organic nanocrystal is constructed from a steric-functionalized difluorene-based organic semiconductor material 2,2′-bi(9,9′-dimethylfluorene) (BMeF). The synthetic nanocrystal presents superior photoelectric integrated properties, with crystallization-enhanced emission and absolute photoluminescence quantum yield (PLQY) up to 75%, high mobility (0.18 cm² V⁻¹ s⁻¹), and low threshold dual-color lasing behavior from ultraviolet (392 nm) to deep-blue (415 nm). Moreover, organic light-emitting diodes (OLEDs) based on BMeF nanocrystals show deep-blue emission with a brightness of 1152 cd m⁻² and turn-on voltage of 2.8 V. This work opens an avenue for high-performance wide-bandgap organic nanocrystals capable of outstanding shortwave emission and high charge mobility.