Highly-ordered vertical Si nanowire/nanowall decorated solar cells

Area of Science:

• Materials Science
• Nanotechnology
• Photovoltaics

Background:

• Silicon solar cells are the dominant photovoltaic technology.
• Surface texturing is crucial for enhancing light absorption and efficiency.
• Nanostructures offer potential for advanced light management in solar cells.

Purpose of the Study:

• To investigate the impact of highly-ordered vertical nanowire and nanowall arrays on silicon solar cell performance.
• To compare the optical reflectance and energy conversion efficiency of nanowall, nanowire, and planar solar cells.
• To analyze the role of series resistance in the performance of nanostructured solar cells.

Main Methods:

• Fabrication of highly-ordered vertical nanowire and nanowall arrays on silicon solar cell surfaces.
• Measurement of optical reflectance across different nanostructured surfaces.
• Characterization of solar cell performance, including short-circuit current (Jsc) and energy conversion efficiency (η).
• Analysis of series resistance (Rs) for various nanostructure types.

Main Results:

• Nanowall textured solar cells demonstrated superior reduction in optical reflectance compared to nanowire and planar cells.
• Short-circuit current (Jsc) was highest for nanowall cells (24.9 mA/cm²), followed by nanowire (23.3 mA/cm²) and planar (17.5 mA/cm²).
• Corrected energy conversion efficiency (η) was highest for nanowall solar cells (9.8%), outperforming nanowire (8.2%) and planar (7.1%) cells.

Conclusions:

• Highly-ordered nanowall arrays are highly effective for silicon solar cell surface texturing, significantly improving light absorption.
• Nanowall structures offer a promising approach to enhance solar cell efficiency by minimizing optical losses.
• Understanding and mitigating series resistance is critical for optimizing the performance of nanostructured solar cells.