Spatial uniformity inspection apparatus for solar cells using a projection display

Area of Science:

• Photovoltaics and Renewable Energy Engineering
• Optical Metrology
• Materials Science

Background:

• Ensuring spatial uniformity of quantum efficiency is critical for maximizing solar cell and module performance.
• Existing methods for uniformity assessment can be time-consuming or lack precision.
• Non-uniformity can lead to reduced power output and premature degradation of solar devices.

Purpose of the Study:

• To develop and demonstrate a measurement apparatus for inspecting the spatial uniformity of solar cell quantum efficiency.
• To quantify the irradiance deviation of the projection system and its correction.
• To evaluate the apparatus's capability in identifying localized efficiency variations in solar cells, modules, and panels.

Main Methods:

• A beam projector system was employed to illuminate the solar cells.
• Gray scale adjustment was used to flatten irradiance deviation within the projection area (1.5×0.8 m) to ±2.6%.
• A 3×3 mm scanning square image was used to map the quantum efficiency of a 15.6×15.6 cm photovoltaic cell.

Main Results:

• The initial irradiance deviation of approximately 200% was corrected to within ±2.6% over a large area.
• Localized quantum efficiency deviations exceeding 10% were identified on the tested solar cell.
• The apparatus successfully demonstrated inspection of spatial uniformity for solar modules and panels.

Conclusions:

• The developed beam projector-based apparatus is effective for precise spatial uniformity inspection of solar cells.
• The system's ability to correct for irradiance non-uniformity and identify localized defects is a significant advancement.
• This technology holds promise for quality control and performance optimization in solar energy applications.