Highly Efficient, Near-Infrared Electrophosphorescence from a Pt-Metalloporphyrin Complex

摘要

Organic light-emitting diodes (OLEDs) have been the subject of a significant research effort for the past two decades with a focus on devices that emit almost exclusively in the visible part of the electromagnetic spectrum.[1] Recently, there has been a growing interest in OLEDs that emit in the near-infrared (NIR) region (700-2500 nm).[2]-[4] Applications for these NIR OLEDs are particularly interesting for night-vision-readable displays[5] and sensors.[6] The efficiency of OLEDs are markedly improved when fluorescent emissive dopants are replaced with phosphorescent heavy-metal complexes that can effectively harvest both the singlet and triplet excitons formed in electroluminescence, with wavelengths (λ) ranging from the near-ultraviolet into the red (with peak emission at λmax=380-650 nm).[7]-[10] Herein, we report on an efficient NIR OLED that utilizes a phosphorescent Pt-metalloporphyrin dopant, with an external quantum efficiency (EQE) greater than 6 % at λmax=765 nm and a full width at half maximum of 31 nm (500 cm-1).