Manipulating crystallization dynamics through chelating molecules for bright perovskite emitters.

Area of Science:

• Materials Science
• Chemistry
• Physics

Background:

• Molecular additives are used to reduce non-radiative recombination in perovskite emitters.
• Chelating (multidentate) molecules are more effective than monodentate ones, a phenomenon not fully explained by passivation alone.

Purpose of the Study:

• To investigate the role of the chelate effect in perovskite crystallization and non-radiative loss mitigation.
• To understand why chelating molecules enhance perovskite light-emitting diode (PeLED) efficiency.

Main Methods:

• Investigated the influence of the chelate effect on perovskite crystallization dynamics.
• Analyzed lead-additive coordination affinity and intermediate phase formation.
• Studied the impact on perovskite nucleation and crystal growth.

Main Results:

• The chelate effect enhances lead-additive coordination, promoting stable intermediate phases.
• It inhibits halide coordination-driven perovskite nucleation, leading to slower crystallization.
• Retarded nucleation and growth result in higher crystal quality and efficient electroluminescence.

Conclusions:

• The chelate effect is critical for controlling perovskite crystallization and minimizing trap-mediated non-radiative losses.
• This finding provides a new perspective on molecular additive design for high-performance PeLEDs.
• Rationalized screening of molecular additives can be improved by considering the chelate effect.