Progress and Future Prospects of Wide-Bandgap Metal-Compound-Based Passivating Contacts for Silicon Solar Cells

Area of Science:

• Materials Science
• Photovoltaics
• Semiconductor Devices

Background:

• Advanced doped-silicon-layer passivating contacts have improved crystalline silicon (c-Si) solar cell power conversion efficiency (PCE) to over 26%.
• Parasitic light absorption in doped silicon layers limits further PCE enhancement.
• Dopant-free passivating contacts (DFPCs) using wide-bandgap metal compounds are emerging as a solution due to reduced parasitic absorption, easier deposition, and lower cost.

Purpose of the Study:

• To review the fundamentals and development status of DFPCs.
• To discuss challenges and potential solutions for enhancing carrier selectivity in DFPCs.
• To outline improvement strategies and future prospects for DFPC design and implementation.

Main Methods:

• Review of existing research and development in DFPCs.
• Analysis and simulations to understand carrier selectivity mechanisms.
• Identification of strategies for optimizing DFPC performance.

Main Results:

• Significant progress has been made in developing electron-selective and hole-selective DFPCs.
• A champion PCE of 23.5% has been achieved with a MoO_x-based hole-selective contact.
• Simulations indicate that DFPCs can achieve PCEs over 26% by tuning carrier concentration and work function.

Conclusions:

• DFPCs present a viable pathway to overcome the limitations of doped silicon contacts.
• Optimizing carrier concentration and work function are key strategies for high-performance DFPCs.
• DFPCs hold significant potential for future advancements in c-Si solar cell technology.