15.7% Efficient 10-μm-thick crystalline silicon solar cells using periodic nanostructures

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Crystalline silicon solar cells are a dominant photovoltaic technology.
• Achieving high efficiency in ultra-thin solar cells presents significant challenges due to light absorption and carrier recombination.
• Advanced light-trapping strategies are crucial for enhancing the performance of thin-film solar devices.

Purpose of the Study:

• To develop and evaluate an advanced light-trapping design for ten micrometer thick crystalline silicon solar cells.
• To achieve record power conversion efficiency and short-circuit current for such thin solar cells.
• To demonstrate the effectiveness of a 2D inverted pyramid photonic crystal and a rear dielectric/reflector stack in enhancing light management.

Main Methods:

• Fabrication of 10-micrometer thick crystalline silicon solar cells.
• Integration of a 2D inverted pyramid photonic crystal structure.
• Implementation of a rear dielectric/reflector stack for enhanced light reflection.
• Characterization of solar cell performance, including short-circuit current and power conversion efficiency.

Main Results:

• The 10-micrometer thick crystalline silicon solar cells achieved a short-circuit current of 34.5 mA cm(-2).
• A power conversion efficiency of 15.7% was recorded for these ultra-thin cells.
• The advanced light-trapping design, combining photonic crystals and a rear stack, was key to the record performance.

Conclusions:

• Ultra-thin crystalline silicon solar cells can achieve high performance with sophisticated light-trapping techniques.
• The demonstrated 2D inverted pyramid photonic crystal and rear dielectric/reflector stack represent a significant advancement in thin-film solar cell technology.
• This work paves the way for more efficient and potentially lower-cost thin crystalline silicon solar cells.