Investigating the Relationship Between the Open-Circuit Voltage of a Photovoltaic Cell and the Cosine of the Angle of Incidence of Light

This investigation explores the relationship between the open-circuit voltage of a monocrystalline photovoltaic cell and the cosine of the angle of incidence of light radiation.

The methodology involves a controlled experiment measuring voltage at angles from 0° to 90°, utilizing six trials per angle to determine mean values. The analysis employs linear regression and rigorous uncertainty propagation for both the measured voltage and the cosine of the angle.

Findings reveal a strong linear correlation (R² = 0.984), qualitatively supporting the cosine law. However, a significant residual voltage at 90° highlights a quantitative deviation from the ideal theoretical model, providing a nuanced evaluation of real-world semiconductor behavior.