Physics - Semiconductors Question with Solution | TestHub

The maximum intensity of solar radiation is in the visible region, which corresponds to an energy of about $1.5\text{ eV}$.

For efficient absorption of solar energy and conversion into electrical energy, the semiconductor material used for a solar cell should have a band gap ($E_g$) close to this value.

Therefore, materials with a band gap between $1.0\text{ eV}$ and $1.8\text{ eV}$ (such as Silicon with $E_g\approx 1.1\text{ eV}$ and GaAs with $E_g\approx 1.43\text{ eV}$) are most suitable for making solar cells.

Answer: between $1.0\mathrm{eV}$ and $1.8\mathrm{eV}$.