Platinum (II) azatetrabenzoporphyrins for near-infrared organic light emitting diodes

This article describes a series ofplatinum (II) azatetrabenzoporphyrin emitters for near-infrared (NIR)organic light emitting diode(OLED) applications.Platinum (II) aza-triphenyltetrabenzoporphyrin (PtNTBP) results in a 72  nm shift in the photoluminescent(PL)emission spectrum to 842  nm compared to 770 nm of theplatinum (II) tetraphenyltetrabenzoporphyrin (PtTPTBP). Also, the full width at half maximum of theemission spectrum of PtNTBP was significantly narrowed to 27  nm compared to 40 nm for PtTPTBP. Themultilayer devicesfabricated by thermal vacuum evaporation process employing PtTPTBP, PtNTBP, and cis-PtN2TBP exhibit electroluminescent(EL) emission peak at 770  nm, 848 nm, and 846 nm with the peak externalquantum efficiency (EQE) of 8.0%, 2.8%, and 1.5%, respectively. Even with the decrease in EQE of devices employing PtNTBP and cis-PtN2TBP compared with those employing PtTPTBP, the combination of thespectral narrowing and the bathochromic shift to lower energyEL emission demonstrates the promise of PtNTBP for NIR applications. In the meanwhile, the solution-processed single-layer device using PtNTBP demonstrates the EQE of 0.33% and the peakEL emission at 844  nm.

Source: Applied Physics Letters - December 5, 2016 Category: Physics Authors: L. Huang, C. D. Park, T. Fleetham and J. Li Source Type: research