Using radiative transfer equation to model absorption by thin Cu(In,Ga)Se2 solar cells with Lambertian back reflector

Area of Science:

• Materials Science
• Renewable Energy
• Optics

Background:

• Thin film solar cells, specifically Copper Indium Gallium Selenide (Cu(In,Ga)Se2), are crucial for renewable energy.
• Optimizing light absorption is key to improving solar cell efficiency.
• Previous simulation methods for light management in solar cells were computationally intensive and lacked physical insight.

Purpose of the Study:

• To investigate and enhance optical absorption in thin Cu(In,Ga)Se2 solar cells.
• To develop a more efficient and insightful model for light management in solar cell configurations.
• To validate the model against experimental optical measurements.

Main Methods:

• Utilized the radiative transfer equation to model the multiple scattering of diffuse light.
• Incorporated wave effects for the collimated part of the light.
• Simulated a thin Cu(In,Ga)Se2 solar cell with a Lambertian white paint and transparent back contact.

Main Results:

• The developed model accurately simulates optical absorption in the specified solar cell configuration.
• The approach provides better physical insight into light absorption mechanisms compared to traditional methods.
• The model's predictions show good agreement with experimental optical measurements.

Conclusions:

• The radiative transfer equation combined with wave optics offers an effective method for simulating light absorption in thin film solar cells.
• This approach overcomes the limitations of computationally expensive Maxwell's equation simulations.
• The findings contribute to the design and optimization of more efficient solar energy devices.