3,6-Di-tert-butyl-carbazolyl disubstituted trifluoromethyl benzene was obtained by single-step synthesis. The compound showed high glass transition temperature of 138 °C. It also exhibited bipolar charge transport with hole mobility of 3.38 × 10−3 cm2/Vs at electric field of 4.87 × 105 V/cm and electron mobility of 2.44 × 10−4 cm2/Vs at the electric field of 5.3 × 105 V/cm. The compound was used in OLEDs as a multifunctional emitter. It appeared to be applicable in UV to white fluorescent devices. A simple three-layers OLED with pristine emitter layer was manufactured and showed a particular property, i.e. voltage-tuneable emission, which varied from the UV to the white one. On the basis of 3,6-di-tert-butyl-carbazolyl disubstituted trifluoromethyl benzene, UV-emitting OLED was obtained that showed a particular feature i.e. voltage-tuneable an ultra-broad spectrum emission from UV (350 nm) to IR (780 nm), whose spectrum is the broadest compared to the reported single molecular emission. At low voltage of 5 V, the device showed electroluminescence in the UV region with a single peak of electroluminescence spectrum at 388 nm and a full width at half maximum (FWHM) bandwidth of 60 nm. After increasing the driving voltage, the device became a white-OLED. In addition, as acceptor of exciplex emitting layer of device, the high-efficiency blue exciplex emission-based OLED (λem= 490 nm) with external quantum efficiency of 9.1% was demonstrated using exciplex-forming system consisting of 3,6-di-tert-butyl-carbazolyl-disubstituted trifluoromethyl benzene and PO-T2T (1:1). The external quantum efficiency value of the exciplex-based OLED was superior compared to those of the previously reported pure exciplex emission-based OLEDs.