Exciplex-Based Organic Light-Emitting Diodes with Near-Infrared Emission

Near-infrared exciplex can weaken molecular design difficulties, and has the advantage of easy bathochromic-shift spectra via selecting the suitable electron donors and acceptors. In this contribution, exciplex is applied to fabricate near-infrared (NIR) organic light-emitting diodes (OLEDs) incorporating a synthesized fluorescent material 3-([1,1 '':3 ',1 ''-terphenyl]-5 '-yl)acenaphtho[1,2-b]pyrazine-8,9-dicarbonitrile (APDC-tPh) and a commercially available material 4,4 ',4 ''-tris(carbazol-9-yl)triphenylamine (TCTA). The device having a mixed TCTA:APDC-tPh as an emitting layer shows a 730 nm NIR emission with a maximum external quantum efficiency (EQE) of about 0.1%, while the device having 2-[4-(diphenylamino)phenyl]-10,10-dioxide-9H-thioxanthen-9-one (TXO-TPA):APDC-tPh as the emitting layer exhibits an emission peak of 704 nm with a maximum EQE of 1.27%. These results prove the feasibility of fabricating the efficient exciplex-based NIR OLEDs.