Single Atomically Sharp Lateral Monolayer p-n Heterojunction Solar Cells with Extraordinarily High Power Conversion...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Renewable Energy

Background:

• 2D monolayer semiconductors enable novel p-n heterojunctions.
• Alloy formation at interfaces limits photovoltaic device efficiency.
• Developing alloy-free heterostructures is crucial for advanced photovoltaics.

Purpose of the Study:

• To investigate the photovoltaic properties of sequentially grown, alloy-free 2D monolayer WSe2-MoS2 lateral p-n heterojunctions.
• To assess the power conversion efficiency and light-harvesting characteristics.
• To explore the feasibility of developing next-generation photovoltaic devices.

Main Methods:

• Sequential growth of alloy-free 2D monolayer WSe2-MoS2 lateral p-n heterojunctions.
• Fabrication and characterization of photovoltaic devices.
• Performance evaluation under AM 1.5G illumination and varying incident angles.
• Device modeling to understand underlying principles.

Main Results:

• Achieved an extraordinary power conversion efficiency of 2.56%.
• Demonstrated excellent omnidirectional light harvesting with only 5% efficiency drop at 75° incident angle.
• Device performance complies with standard photovoltaic principles.
• Environment-independent properties observed with optimized electrode spacing.

Conclusions:

• Atomically sharp lateral p-n interfaces in 2D heterostructures lead to robust photovoltaic properties.
• These findings support the development of high-efficiency, next-generation photovoltaics.
• Alloy-free growth is a viable strategy for advanced 2D material-based solar cells.