Molecularly Templated Buried Interfaces for Inverted Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Organic Electronics

Background:

• The buried interface between self-assembled monolayers (SAMs) and perovskite absorbers is crucial for charge extraction and stability in inverted perovskite solar cells.
• This interface is often structurally mismatched and poorly controlled, limiting device performance.

Purpose of the Study:

• To develop a buried-interface engineering strategy for inverted perovskite solar cells using non-covalent molecular templating.
• To improve the structural organization, adhesion, and electronic properties at the SAM/perovskite interface.

Main Methods:

• Utilized complementary triphenylamine-based molecular building blocks for non-covalent molecular templating.
• Introduced a triphenylamine-based ammonium salt (TPANI) into the perovskite precursor.
• Deposited a triphenylamine-based bisphosphonic acid SAM on ITO as the hole-selective layer.

Main Results:

• Non-covalent interactions induced molecular templating and interfacial organization of TPANI.
• Strengthened SAM/perovskite adhesion and reduced intergranular groove depth.
• Achieved a power conversion efficiency of 26.58% and an 86.72% fill factor in inverted devices.
• Demonstrated markedly enhanced operational stability.

Conclusions:

• Non-covalent molecular templating is an effective strategy for engineering buried interfaces in perovskite photovoltaics.
• The developed strategy suppresses interfacial defects, improves energy-level alignment, and facilitates hole extraction.
• This approach leads to high-performance and stable inverted perovskite solar cells.