Question

Why GaAs is preferred over Si in a solar cell?

• A. Because GaAs is easily available
• B. Because GaAs has relatively higher absorption coefficient
• C. Because GaAs has lower energy gap
• D. Because GaAs is cheaper

Answer 1

Answer: (B)

Because GaAs has relatively higher absorption coefficient
When subjected to radiation exposure, a GaAs cell is more resistant than a silicon cell due to its direct band gap and resultant high photon absorption coefficient. As such, less film thickness i required in the GaAs cell to absorb solar radiation.