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Question
Answer the following question.
Explain the three processes involved in solar cell working.
Solution
The generation of emf by a solar cell, when light falls on, it is due to the following three basic processes: generation, separation and collection
- generation of e-h pairs due to light (with hν > Eg) close to the junction
- separation of electrons and holes due to electric field of the depletion region. Electrons are swept to n-side and holes to p-side
- the electrons reaching the n-side are collected by the front contact and holes reaching the p-side are collected by the back contact. Thus the p-side becomes positive and the n-side becomes negative giving rise to photo-voltage.
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