In conclusion, we presented two deep-blue p,n-doped nanographene emitters (1B-DTACrs and 2B-DTACrs), in which 2B-DTACrs with two boron atoms is TADF-active while 1B-DTACrs with only one boron atom is TADF inactive. Devices based on 2B-DTACrs achieved a high EQEmax of 14.8% and CIEx,y of (0.150, 0.044), which are one of highest efficiency deep-blue MR-TADF devices reported to date. Importantly, the CIE coordinates effectively meet the colour gamut requirement for the BT.2020 standard for the blue pixel.