Solar CellEasyQuestion 20225
Question
A solar cell works on the principle of:
- Ap-n junction in forward bias
- Bp-n junction in reverse bias
- CPhotovoltaic effect — light creates electron-hole pairs that are separated by the junction fieldCorrect
- DThermoelectric effect
Correct answer
Photovoltaic effect — light creates electron-hole pairs that are separated by the junction field
Explanation
Incident photons of energy hf > Eg create electron-hole pairs. The built-in field at the p-n junction sweeps electrons to n-side and holes to p-side → EMF is generated → current flows in external circuit. Open-circuit voltage ≈ 0.5–0.7 V per cell for Si.