Enhanced Brightness Through Rational Design of Hole Transport Layer for Blue Perovskite Light-Emitting Diodes

Area of Science:

• Optoelectronics
• Materials Science

Background:

• Blue perovskite light-emitting diodes (PeLEDs) face limitations in brightness and operational stability, hindering full-color display development.
• A key challenge is the significant hole injection barrier at the interface between hole-transporting layers (HTLs) and blue perovskite emissive layers.

Purpose of the Study:

• To address the performance bottlenecks in blue PeLEDs by developing novel interfacial modification strategies.
• To design and synthesize organic small molecules for modifying the PEDOT:PSS HTL to improve hole injection and device stability.

Main Methods:

• Synthesized two novel organic small molecules, MPFO and MPFO-MAP, for interfacial modification.
• Applied MPFO-MAP to the PEDOT:PSS HTL in blue PeLEDs.
• Characterized the performance of modified and pristine PeLED devices, focusing on luminance, external quantum efficiency, and stability.

Main Results:

• MPFO-MAP effectively reduced the hole-injection barrier and passivated interfacial defects.
• The modified PeLEDs exhibited a 2.9-fold increase in maximum luminance (8272 cd/m²) and a 3.7-fold increase in external quantum efficiency (12.6%).
• MPFO-MAP facilitated balanced charge transport and enhanced radiative recombination.

Conclusions:

• The dual-function non-protic interfacial engineering strategy using MPFO-MAP significantly improves blue PeLED performance.
• This molecular design approach offers a versatile blueprint for high-brightness blue PeLEDs and other perovskite optoelectronic devices.
• The findings pave the way for practical applications of perovskite-based displays.