Q.State the principle and uses of a solar Cell.

[!TLDR] A solar cell works by the photovoltaic effect -- light-generated carriers, separated by the p-n junction's built-in field, produce a voltage and current -- and is used wherever standalone, low-maintenance DC power generation from sunlight is needed. [!ANSWER] Principle: the photovoltaic effect at an illuminated p-n junction, where photo-generated electron-hole pairs are separated by the junction's field to produce a voltage and (wit …

PRINCIPLE: a solar (photovoltaic) cell is a large-area p-n junction whose thin n-side faces the incident sunlight. When photons of energy greater than the semiconductor's band gap strike the depletion region, they generate electron-hole pairs there; the junction's own built-in electric field immediately separates these pairs -- sweeping electrons into the n-region and holes into the p-region -- before they can recombine. This separation accumulates net negative charge on the n-side and net positive charge on the p-side, building up a voltage across the cell; when an external circuit is connected across the cell's terminals, this accumulated charge drives a current (the photo-generated or light-generated current) through the load, directly converting incident light energy into usable electrical power. USES: because solar cells require no fuel, produce power silently and without moving parts, need relatively little maintenance, and can operate wherever sunlight reaches (including places with no other power infrastructure), they are widely used for: charging batteries during daylight hours so stored power is available at night; powering equipment at remote locations, from small calculators up to satellites and space stations; supplying po …

State the photovoltaic effect (light generates and separates carriers at a p-n junction, producing voltage and current) as the principle, then list the pract …

Confusing the solar cell's principle with the photothermal (solar-water-heating) mechanism mentioned earlier in the same section -- the solar cell specifically converts …