a A comparison of EL intensity of the neat and blend BSBCz-EH OLEDs at a current density of 50 A cm−2. b Normalised EL intensities, showing a significant STA in the neat device and substantial reduction of the same in blend. c EQE versus current density for neat and blend devices at 50 A cm−2. d Brightness versus current density plot for neat and blend devices. OLED area = 0.2 mm2; pulse widths = 100 ns.