Silicon heterojunction back-contact solar cells by laser patterning

Area of Science:

• Materials Science
• Renewable Energy Engineering
• Photovoltaics

Background:

• Back-contact silicon solar cells offer aesthetic advantages and are suitable for building-integrated photovoltaics.
• Current patterning techniques complicate manufacturing and lead to power losses.
• There is a need for efficient and streamlined fabrication methods for high-performance solar cells.

Purpose of the Study:

• To develop a laser-based fabrication process for back-contact silicon solar cells.
• To enhance the power-conversion efficiency of these solar cells.
• To reduce manufacturing complexity and processing time.

Main Methods:

• Utilized pulsed picosecond lasers at various wavelengths for back-contact patterning.
• Developed a novel dense passivating contact structure.
• Deposited hydrogenated amorphous silicon layers for surface passivation and carrier collection.

Main Results:

• Achieved a silicon solar cell power-conversion efficiency exceeding 27%.
• Developed indium-less cells at 26.5% efficiency and silver-free cells at 26.2% efficiency.
• Reduced the effective processing time to approximately one-third of emerging mainstream technologies.

Conclusions:

• Laser-based fabrication offers a streamlined and efficient method for producing high-performance back-contact silicon solar cells.
• The developed technology facilitates the integration of solar solutions into buildings and transportation.
• This advancement supports the expansion of solar energy to meet terawatt demands.