Direct-Patterning SWCNTs Using Dip Pen Nanolithography for SWCNT/Silicon Solar Cells

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Single-walled carbon nanotubes (SWCNTs) offer excellent conductivity for solar cell applications.
• Efficient patterning of SWCNTs is crucial for fabricating high-performance SWCNT/Si solar cells.
• Current methods for SWCNT patterning face limitations in scalability and line length.

Purpose of the Study:

• To optimize dip pen nanolithography (DPN) for patterning long, uniform SWCNT lines.
• To integrate patterned SWCNT lines as conductive pathways in SWCNT/Si solar cells.
• To evaluate the impact of SWCNT lines on solar cell performance.

Main Methods:

• Optimized SWCNT ink composition, loading, and DPN pretreatment for improved patterning.
• Utilized DPN to create SWCNT lines exceeding 1 mm in length.
• Fabricated SWCNT/Si solar cells incorporating the patterned SWCNT lines.
• Characterized SWCNT uniformity using Raman spectroscopy and scanning electron microscopy.
• Measured critical solar cell parameters including power conversion efficiency, series resistance, and fill factor.

Main Results:

• Successfully patterned SWCNT lines over 1 mm long, a 20-fold increase in length.
• Demonstrated the scalability of DPN for patterning larger areas with SWCNTs.
• SWCNT/Si solar cells with patterned lines showed a 40% relative increase in power conversion efficiency.
• Average series resistance decreased by 44%, and average fill factor increased by 24%.

Conclusions:

• Optimized DPN is a scalable technique for fabricating long SWCNT lines for solar cells.
• Patterned SWCNT lines significantly enhance the performance of SWCNT/Si solar cells.
• DPN-patterned SWCNT lines represent a promising approach for efficient solar energy conversion.