Multi-Material Front Contact for 19% Thin Film Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• The front contact material's transmittance-conductivity trade-off limits thin film solar panel efficiency.
• Metal oxides are common front contact materials, with optimal configurations studied for CIGS, CdTe, and perovskite solar cells.

Purpose of the Study:

• To investigate the impact of metallic finger grids on front contact performance in thin film solar panels.
• To determine optimal front contact designs by varying TCO sheet resistance, cell length, and finger dimensions.

Main Methods:

• Simulations were performed to analyze various front contact designs with and without metallic finger grids.
• Key parameters assessed included TCO sheet resistance, scribing area, cell length, finger dimensions, contact resistance, and illumination power.

Main Results:

• Supplementing transparent conductive oxides (TCOs) with a metallic finger grid significantly improves solar cell efficiency.
• The addition of a metallic grid enables longer cell lengths, enhancing overall panel design.
• Contact resistance between the metal grid and TCO material was found to partially offset the efficiency improvements.

Conclusions:

• Metallic finger grids are a viable strategy to overcome the limitations of TCOs in thin film solar panels.
• Optimizing the design, including managing contact resistance, is crucial for maximizing efficiency gains.
• This approach offers a pathway to higher-performing and potentially more cost-effective thin film solar technologies.