Ordered Element Distributed C₃ N Quantum Dots Manipulated Crystallization Kinetics for 2D CsPbI₃ Solar Cells with...

Area of Science:

• Materials Science
• Nanotechnology
• Photovoltaics

Background:

• Two-dimensional (2D) CsPbI3 perovskites face phase-stability challenges due to bulky organic cations.
• These cations increase formation energy and hinder crystallization kinetics, leading to poor phase arrangement and device performance.

Purpose of the Study:

• To address the phase-stability and crystallization issues in 2D CsPbI3 perovskites.
• To improve the crystallization pathway, phase arrangement, and morphology of 2D CsPbI3 films using C3N quantum dots (QDs).

Main Methods:

• Utilized C3N quantum dots with ordered carbon and nitrogen atoms.
• Employed theoretical simulation, morphology regulation, and femtosecond transient absorption (fs-TA) characterization.
• Investigated the role of C3N QDs in adsorbing organic cations and providing nucleation sites for bi-directional crystallization.

Main Results:

• C3N QDs facilitated a bi-directional crystallization process, improving the quality of 2D CsPbI3 films.
• Achieved lower trap density, higher surface potential, and more compact film morphology.
• Optimized devices demonstrated a power conversion efficiency (PCE) of 15.63% with enhanced environmental stability.

Conclusions:

• C3N QDs effectively manipulate the crystallization of 2D CsPbI3, overcoming phase-stability limitations.
• The QD-based strategy enhances optoelectronic properties and device performance.
• This method shows universality for various perovskite structures, offering a promising modulation strategy for optoelectronic devices.