Interfacial Engineering at the 2D/3D Heterojunction for High-Performance Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Two-dimensional/three-dimensional (2D/3D) perovskite solar cells offer enhanced photovoltaic performance and stability.
• Understanding the interfacial mechanisms at the 2D/3D heterojunction is crucial for further advancements.

Purpose of the Study:

• To investigate the ligand-chemistry-dependent nature of the 2D/3D heterojunction.
• To elucidate the influence of interfacial engineering on charge collection and photovoltaic outcomes.

Main Methods:

• Demonstration of 3D phase templates for quantum well (QW) growth within a 2D capping layer.
• Utilizing fluorination of spacers and compositional engineering (thickness, orientation) of QWs.
• Analysis of charge transfer dynamics and recombination losses at the 2D/3D heterojunction.

Main Results:

• Achieved better quantum well alignment and faster charge transfer dynamics at the 2D/3D heterojunction.
• Observed higher charge mobility and reduced charge recombination loss.
• Demonstrated a power conversion efficiency of 21.15% for 2D/3D solar cells, surpassing the 19.02% efficiency of 3D counterparts.

Conclusions:

• Interfacial engineering via ligand chemistry and compositional control significantly improves electronic properties of 2D/3D hierarchical films.
• Optimized interfacial mechanisms lead to enhanced charge collection and higher open-circuit voltage (VOC).
• This study provides critical insights into the structure-property relationships for high-performance perovskite solar cells.