Light-harvesting using high density p-type single wall carbon nanotube/n-type silicon heterojunctions

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Developing efficient and cost-effective photovoltaic devices is crucial for renewable energy.
• Carbon nanotubes offer unique electronic properties for potential solar cell applications.

Purpose of the Study:

• To create and characterize photovoltaic devices using single-wall carbon nanotubes (SWNTs) and n-type silicon.
• To investigate the effect of chemical modification on the performance of SWNT/silicon heterojunctions.

Main Methods:

• Fabrication of p-n heterojunctions using airbrushed SWNT networks on n-type crystalline silicon.
• Chemical modification of SWNT films using thionyl chloride (SOCl2).
• Characterization of photovoltaic properties, including power conversion efficiency.

Main Results:

• Successful formation of high-density p-n heterojunctions exhibiting rectifying behavior.
• SWNTs acted as both photogeneration sites and charge transport layers.
• Thionyl chloride treatment increased conversion efficiency by over 50% by optimizing carrier concentration and mobility.
• Achieved a power conversion efficiency exceeding 4%.

Conclusions:

• The SWNT/n-Si heterojunction is a viable low-cost material for photovoltaic applications.
• Chemical modification of SWNTs significantly enhances solar cell performance.
• This approach offers a promising route for efficient and affordable solar energy harvesting.