Stable and Efficient Near-Infrared Organic Light-Emitting Diodes Employing a Platinum(II) Porphyrin Complex

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Near-infrared organic light-emitting diodes (NIR OLEDs) are crucial for applications like biometric authentication and telecommunication.
• Developing NIR OLEDs with emission spectra beyond 900 nm is an ongoing technological challenge.
• Heavy platinum(II) porphyrin complexes often suffer from thermal instability, limiting their use in devices.

Purpose of the Study:

• To report a novel, stable, and efficient near-infrared Pt(II) porphyrin complex for NIR OLEDs.
• To achieve NIR emission beyond 900 nm with high quantum efficiency and operational stability.
• To address the thermal instability common in heavy Pt(II) porphyrin complexes.

Main Methods:

• Synthesis and characterization of a new Pt(II) porphyrin complex, PtTPTNP-F8, featuring fluorine atoms at meta positions.
• Fabrication of NIR OLED devices using PtTPTNP-F8 as the emissive material with carefully selected host materials.
• Evaluation of device performance, including emission spectrum, sublimation yield, peak device efficiency, and operational stability (LT99 lifetime).

Main Results:

• PtTPTNP-F8 exhibits 84% of emitted photons at wavelengths longer than 900 nm.
• The fluorine substitution enhances thermal stability, achieving a sublimation yield above 90%.
• The optimized NIR OLED device demonstrates a peak efficiency of 1.9% and an extraordinary operational stability with an LT99 lifetime exceeding 1000 hours at 20 mA cm-2.

Conclusions:

• PtTPTNP-F8 is a highly promising emissive material for stable and efficient NIR OLEDs operating beyond 900 nm.
• The strategic introduction of fluorine atoms effectively mitigates thermal degradation issues in Pt(II) porphyrin complexes.
• This work paves the way for advanced NIR OLED applications requiring long-wavelength emission and robust device performance.