Fig. 1: Radical energy harvesting design for high-efficiency NIR emission.
From: Efficient near-infrared organic light-emitting diodes with emission from spin doublet excitons
a, Schematic illustration of intersystem dual energy transfer between host MADN and radical TTM-TPA in doublet EL devices. DET, Dexter energy transfer. b, Chemical structures of TTM-TPA, CBP and MADN. c, Absorption coefficient for TTM-TPA in toluene, as well as film PL spectra of CBP neat, MADN neat and TTM-TPA 3% doped in CBP and MADN. The spectral overlap between TTM-TPA absorption (open green squares) with CBP (filled blue circles) and MADN (filled red triangles) PL allows singlet–doublet energy transfer.
