Optimization of selective emitter fabrication method for solar cells using a laser grooving

Area of Science:

• Photovoltaics
• Semiconductor device fabrication

Background:

• Screen-printed solar cells are a dominant technology.
• Existing infrastructure limits efficiency gains.
• Laser grooved buried contact (LGBC) offers a path to higher performance.

Purpose of the Study:

• To optimize the screen-printing LGBC method for high-efficiency solar cells.
• To enhance short circuit current (Isc), open circuit voltage (Voc), and fill factor.
• To demonstrate the applicability of LGBC for commercial solar cell production.

Main Methods:

• Applied screen-printing LGBC technique compatible with existing facilities.
• Optimized doping profiles: heavy doping at low sheet resistance in laser-grooved regions, light doping at high sheet resistance in non-laser-grooved regions.
• Removed porous silicon post-HF treatment to improve fill factor.

Main Results:

• Achieved a 17.2% conversion efficiency for a screen-printed LGBC solar cell.
• Demonstrated significant improvements in Isc, Voc, and fill factor through optimized doping and surface treatment.
• Successfully fabricated LGBC solar cells on 125 mm x 125 mm single crystalline silicon wafers.

Conclusions:

• The screen-printing LGBC method is a viable approach for manufacturing high-efficiency solar cells.
• The optimized doping and surface treatment strategies are effective in boosting solar cell performance.
• This technology can be integrated into existing solar cell production lines.