Reducing shadowing losses in silicon solar cells using cellulose nanocrystal: polymer hybrid diffusers

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Gridline shadowing significantly reduces silicon solar cell performance.
• Metallic contacts on solar cells cause light loss due to shadowing.
• Minimizing shadowing is crucial for improving solar energy conversion efficiency.

Purpose of the Study:

• To develop a straightforward and scalable method to reduce shadowing losses in silicon solar cells.
• To utilize cellulose nanocrystals (CNC) and a polymer matrix for light diffusion.
• To enhance the efficiency of solar cells by redirecting light away from metallic gridlines.

Main Methods:

• A hybrid material composed of cellulose nanocrystals (CNC) and polydimethylsiloxane (polymer) was synthesized.
• The CNC:polymer (CNP) diffusers were applied atop the metallic contact areas of silicon solar cells.
• Simulations were performed to evaluate the light diffusion and light recycling capabilities of the CNP diffusers under various incident angles.

Main Results:

• The CNP diffusers demonstrated highly efficient broadband light diffusion, deflecting light from gridlines to active cell areas.
• Simulations indicated a reduction of over 30% in shadowing losses at normal incidence.
• Nearly 50% of lost light was recycled at a 60° incident angle, showcasing effectiveness across a wide range of angles.

Conclusions:

• The developed CNC:polymer diffusers offer a promising solution for mitigating shadowing losses in silicon solar cells.
• This method is compatible with existing solar cell module manufacturing processes.
• A novel 6-busbar solar cell technology utilizing CNP diffusers is proposed, promising lower manufacturing complexity and higher overall efficiency.