Tailoring Extremely Narrow FWHM in Hypsochromic and Bathochromic Shift of Polycyclo‐Heteraborin MR‐TADF Materials for High‐Performance OLEDs

) of 33.7 and 29.8 % for NO-DBMR and Cz-DBMR, respectively. This is the first work reported with this type of strategy for achieving an extremely narrow emission spectrum in hypsochromic and bathochromic shifted emissions with a similar molecular skeleton.