17.6%-Efficient radial junction solar cells using silicon nano/micro hybrid structures

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Surface recombination and limited light absorption hinder solar cell efficiency.
• Existing planar and microwire structures have suboptimal performance.

Purpose of the Study:

• To develop a novel nano/micro hybrid structure for enhanced solar cell performance.
• To investigate the light absorption and efficiency improvements offered by the hybrid structure.

Main Methods:

• Fabrication of a nano/micro hybrid structure using metal-assisted chemical etching.
• Selective modification of microwire tops to create nanostructures.
• Characterization of light absorption and photovoltaic performance under AM 1.5G illumination.

Main Results:

• The hybrid structure achieved 97% light absorption, significantly outperforming planar (59%) and microwire (85%) structures.
• Solar cells with the hybrid structure demonstrated a power conversion efficiency (Eff) of 17.6%.
• A high short-circuit current density (Jsc) of 39.5 mA cm(-2) was recorded due to enhanced light absorption.

Conclusions:

• The nano/micro hybrid structure effectively minimizes surface recombination and maximizes light absorption.
• The developed hybrid solar cells show a substantial increase in efficiency compared to planar and microwire designs.
• This hybrid structure is a foundational technology for developing highly efficient radial junction solar cells.