showed similarly low turn on (Von) voltages of 3.5 V, high EQEmax of 34.9% and 34.3%, and maximum luminance of (Lummax) of 18 400 and 11 200 cd m -2 , respectively. This is a significant improvement compared to the reported device with BTC-BNCz, which showed an EQEmax and Lummax of 27.0%, and 8 500 cd m -2 , respectively. Benefiting from the faster kRISC, the OLED with tCzBT2B showed a suppressed efficiency roll-off, with EQE remaining at 22.5% at 1000 cd m -2 , whereas the EQE1000 for the device with tCzBT1B reduced to 18.0%. The devices with tDPABT1B and tDPABT2B showed slightly bluer emission with λEL of 491 and 492 nm, FWHM of 0.15 eV (31 nm) and 0.15 eV (31 nm), and CIE coordinates of (0.13, 0.31) and (0.13, 0.30), respectively. The Von are 4.5 V for both, and due to their relatively lower ΦPL values and slower kRISC, the devices with tDPABT1B and tDPABT2B