Towards 27% efficient silicon solar cells in mass production

Dr. Daniel MacDonald from The Australian National University presents a detailed loss analysis of champion efficiency TOPCon solar cells and a roadmap towards 27% efficient silicon solar cells in mass production. This presentation provides an in-depth examination of the various loss mechanisms in high-efficiency TOPCon devices.

Key findings include:

• Comprehensive loss analysis using SunSolve ray tracing for optical losses and Quokka 3D simulations for electrical losses
• Identification of infrared escape as the largest single optical loss due to light trapping below the Lambertian limit
• Analysis showing Auger recombination as the dominant loss mechanism, representing an intrinsic efficiency limit
• Significant transport losses due to large contact spacing (>5x cell thickness)
• Roadmap improvements including reduced finger width (30%), improved surface passivation, high resistivity wafers, and optimized contact geometry

The analysis demonstrates that with realistic near-term improvements - including thinner front fingers, reduced polysilicon parasitic absorption, and optimized contact geometry - efficiencies of just over 27% are achievable within 12-18 months. The work provides critical insights for the photovoltaic industry on the path toward higher efficiency silicon solar cells in commercial production.