A Multifunctional Additive Strategy Enables Efficient Pure-Blue Perovskite Light-Emitting Diodes

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Chemistry

Background:

• Perovskite light-emitting diodes (PeLEDs) show promise for efficient light emission across various wavelengths.
• Achieving satisfactory pure-blue emission (465-475 nm) in PeLEDs remains a significant challenge.
• Existing blue PeLEDs often suffer from instability and low efficiency.

Purpose of the Study:

• To develop efficient and stable pure-blue PeLEDs.
• To investigate the role of multifunctional additives in controlling perovskite film properties.
• To enhance charge transport and reduce defects for improved device performance.

Main Methods:

• Fabrication of reduced-dimensional perovskite films with controlled phase distribution.
• Utilizing multifunctional phenylethylammonium trifluoroacetate (PEATFA) as an additive.
• Surface modification and defect passivation of perovskite films.

Main Results:

• The additive strategy facilitated the formation of large-n low-dimensional perovskites, enhancing charge transport.
• Trifluoroacetate (TFA-) interaction with perovskites significantly reduced film defects.
• The modified films exhibited improved radiative recombination and carrier transport.
• The resulting pure-blue PeLEDs achieved a maximum external quantum efficiency (EQE) of 11.87% at 468 nm with stable spectral output.

Conclusions:

• Multifunctional additive engineering is a viable strategy for high-efficiency pure-blue PeLEDs.
• The developed PeLEDs represent a significant advancement in blue light emission for perovskite technology.
• This work paves the way for high-performance blue LEDs based on perovskite polycrystalline films.