“…Jayabharathi et al 161 reported the preparation of M-shaped TPA-2SPPITPA/TPA-2PPITPA emitters with the twist angle of absorption at a longer wavelength and the absorption onset became red-shifted compared to Ph-BPA-BPI due to the stronger ÀI ability of pyrene than phenanthrene. In polar solvent, a hypsochromic shift of 14 nm was observed for Py-BPA-BPI due to the formation of the TICT state and LE state in the aggregated solid due to the restricted intramolecular rotation [T g , T d : 196 The smaller injection barrier facilitated efficient h + and e À injection into the EML@low V. The BOLEDs [ITO/NPB (70 nm)/ TCTA (5 nm)/Ph-BPA-BPI/Py-BPA-BPI (30 nm)/TPBI (40 nm)/LiF (1 nm)/Al (150 nm)] showed the EL of 448/471 nm; CE of 3.60/ 10.9 cd A À1 ; PE of 3.66/10.5 lm W À1 ; EQE of 4.56/5.64%; EUE of 36.2/39.2%; and CIE of (0.15, 0.08)/(0.17, 0.29), respectively.…”