Luminescent carbene-copper(i)-amide polymers for efficient host-free solution-processed OLEDs

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Luminescent metallopolymers are crucial for healthcare and organic electronics.
• Development of polymeric emitters using earth-abundant metals remains limited.

Purpose of the Study:

• To synthesize and characterize novel copper(I) polymers for potential use in organic light-emitting diodes (OLEDs).
• To investigate the photophysical properties and device performance of these new metallopolymers.

Main Methods:

• Synthesis of two series of Cu(I) polymers (PMAC-x and PCAAC-x) with carbene-metal-amide (CMA) complexes grafted onto a polystyrene backbone.
• Characterization of photoluminescence quantum efficiency, emission lifetimes, and radiative rates in neat films.
• Fabrication and testing of host-free, solution-processed OLED devices.

Main Results:

• The Cu(I) polymers exhibit distinct thermally activated delayed fluorescence or phosphorescence.
• PMAC-x polymers show high photoluminescence quantum efficiencies (up to 0.78), short lifetimes (down to 0.66 μs), and fast radiative rates (up to 10^6 s^-1).
• The polymers demonstrate good moisture stability and aggregation-induced emission, leading to OLEDs with a record external quantum efficiency of 13.8%.

Conclusions:

• This work introduces the first carbene-metal-amide (CMA) polymers.
• These metallopolymers represent a significant advancement for OLED applications, utilizing earth-abundant metal complexes.
• The findings provide a promising direction for developing efficient polymeric emitters for next-generation electronic devices.