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In photovoltaics , the study of conversion of light energy into electrical energy.
The Shockley-Queisser limit is a theoretical concept that defines the maximum capacity of a solar cell to produce electricity.
The Sun is the primary source of light and energy on the earth.
Photovoltaic devices like solar cells allow us to harness this energy.
Photovoltaic cells are made of semiconducting materials like (doped) silicon.
When sunlight interacts with a semiconductor, it excites electrons from the lower-energy valence band to the higher-energy conduction band.
ShockleyQueisser limit
We know that the efficiency with which a solar cell can produce an electric current when sunlight is incident on it can’t be 100% because some light particles (photons) pass through the material without interacting with it.
Some energy simply heats up the material without exciting the electrons (thermalisation, around 30%).
As a result, the maximum efficiency of a conventional solar cell is confined, and this range is called the Shockley-Queisser limit.
It is named after the physicists William Shockley (of the U.S.) and Hans-Joachim Queisser (Germany).
What is Photovoltaics?
Photovoltaics refers to the technology of converting light energy directly into electricity.
Core principle: Photovoltaics utilizes the photovoltaic effect, a phenomenon where certain materials, like semiconductors, absorb sunlight and release electrons.
These freed electrons can then be directed to flow through a circuit, generating electricity.
Components: The basic building block of PV technology is the solar cell.
Solar cells: These are small units made from specialized semiconductor materials.
When sunlight hits the cell, the photovoltaic effect occurs, producing a small amount of electricity (typically 1-2 watts per cell).
Solar panels: Multiple solar cells are wired together to form larger units called modules or panels.
This increases the overall electricity generation capacity.
Applications:
Solar power generation: Photovoltaic panels are most commonly used in solar power systems. These systems can be:
Grid-connected: Generate electricity that feeds into the power grid.
Stand-alone: Power individual homes, businesses, or remote locations.
Other applications: PV technology also finds uses in:
Calculators and small electronics: Powering small devices.
Road signs: Providing electricity for lights and displays.
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