High Performance Inverted Perovskite Solar Cells via Heteroatom-Containing Multifunctional Spiro Self-Assembled...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) require optimized hole-transporting layers for high efficiency and stability.
• Self-assembled monolayers (SAMs) play a crucial role in the interface engineering of PSCs.
• Understanding the interaction between SAMs and perovskite layers is key to device performance.

Purpose of the Study:

• To develop novel spiro SAMs with heteroatoms (O and S) for enhanced PSC performance.
• To investigate the impact of molecular structure and heteroatom incorporation on perovskite film quality and interfacial properties.
• To achieve high power conversion efficiency and improved operational stability in inverted PSCs.

Main Methods:

• Synthesis of two spiro SAMs: Spiro-O and Spiro-S, incorporating oxygen and sulfur atoms, respectively.
• Fabrication of inverted perovskite solar cells using the developed SAMs as hole-transporting layers.
• Characterization of SAMs, perovskite films, and device performance using experimental and theoretical techniques.

Main Results:

• Spiro-S exhibits stronger interaction with the perovskite layer compared to Spiro-O, leading to a more uniform and higher-quality crystalline film.
• The sulfur atom in Spiro-S effectively passivates defects at the perovskite/SAM interface, reducing charge recombination.
• PSCs utilizing Spiro-S achieved a power conversion efficiency of 25.75% (certified 25.19%) and retained 92% of initial efficiency after 1200 hours of storage.

Conclusions:

• Incorporating sulfur into spiro SAMs is a promising strategy for enhancing perovskite solar cell performance.
• The Spiro-S SAM improves perovskite film quality and interfacial passivation, leading to significant gains in efficiency and stability.
• This work demonstrates the potential of tailored SAMs for advancing perovskite solar cell technology.