Highly Efficient and Stable SnO₂-Based Inverted Organic Solar Cells Modified with a Simple Small Molecule Exceeding...

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Organic solar cells (OSCs) are a promising renewable energy technology.
• Electron transport layers (ETLs) like tin oxide (SnO₂) are crucial for OSC performance.
• Defects and work function of ETLs can limit charge extraction and device efficiency.

Purpose of the Study:

• To investigate the effect of bathocuproine (BCP) functionalization on SnO₂ ETLs in inverted organic photovoltaic devices.
• To understand the interfacial interactions between BCP and SnO₂ and their impact on device performance.
• To enhance the power conversion efficiency (PCE) and operational stability of inverted OSCs.

Main Methods:

• Theoretical quantum chemical calculations to study BCP-SnO₂ interactions.
• Experimental fabrication and characterization of inverted OSCs with modified SnO₂ ETLs.
• Device performance testing including PCE measurements and stability assessments (storage, light, thermal, humidity, UV).

Main Results:

• BCP functionalization effectively reduces the work function and improves the conductivity of SnO₂.
• Interfacial interactions passivate SnO₂ surface defects, reducing charge recombination.
• BCP-modified devices show significantly improved PCEs, reaching up to 19.13% for ternary OSCs.
• Enhanced device stability with T₈₀ exceeding 500 hours, a substantial improvement over unmodified devices.

Conclusions:

• BCP is an effective material for functionalizing SnO₂ ETLs in inverted OSCs.
• The BCP-SnO₂ interface modification leads to superior charge transport and reduced recombination.
• This strategy offers a pathway to high-efficiency and stable inverted organic solar cells.