Diethanolamine Modified Perovskite-Substrate Interface for Realizing Efficient ESL-Free PSCs.

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Electron-selective layers (ESLs) in perovskite solar cells (PSCs) add complexity and high-temperature processing steps.
• ESL-free PSCs offer simplified fabrication but suffer from poor interfacial charge extraction and limited power conversion efficiency (PCE).

Purpose of the Study:

• To develop a simplified fabrication method for high-efficiency and stable ESL-free PSCs.
• To improve the perovskite/substrate interface quality and suppress charge recombination in ESL-free PSCs.

Main Methods:

• Insertion of a diethanolamine (DEA) molecular monolayer between the indium tin oxide (ITO) substrate and the perovskite layer.
• Characterization of perovskite thin film morphology, interfacial properties, and device performance.

Main Results:

• Formation of a compact, homogenous perovskite thin film with large grains on DEA-treated ITO.
• Suppression of charge recombination due to a favorable dipole layer created by DEA adsorption at the ITO/perovskite interface.
• Achieved a maximum PCE of 20.77% in ESL-free PSCs, demonstrating high performance.
• Enhanced device stability, retaining 80% of initial PCE after 550 hours of continuous operation.

Conclusions:

• The DEA interfacial monolayer is an effective strategy for fabricating high-performance and stable ESL-free PSCs.
• This approach simplifies PSC fabrication by eliminating the need for ESLs and high-temperature treatments.
• The study highlights the potential of molecular engineering at interfaces to overcome limitations in perovskite solar cell technology.