Q.a) Convert the binary number 10011 into decimal equivalent. b) What is solar cell? Why are Si and Ga-As preferred materials for solar cell? Give its V-I characteristics. OR

A solar cell is a p-n junction that generates an emf from absorbed light via the photovoltaic effect -- electron-hole pairs created by photons are separated by the junction field.

Working

A solar cell is a large-area p-n junction. Photons of energy greater than the band gap generate electron-hole pairs near the junction; the junction's built-in field sweeps electrons to the n-side and holes to the p-side, producing an emf without external bias -- this is the photovoltaic effect/action, the operating principle of the solar cell. Di …

A solar cell generates a voltage/current by the photovoltaic effect: light-generated electron-hole pairs are separated by the p-n junction's built-in field.

Working

A solar cell is essentially a large-area, specially designed p-n junction. When photons of energy greater than the semiconductor's band gap fall on the junction, they generate electron-hole pairs in and near the depletion region. The junction's built-in electric field sweeps the generated electrons to the n-side and holes to the p-side, producing an emf across the junction without any external bias -- this is the photovoltaic action/effect, the operating principle of a solar cell.

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