Silicon PV Cells: Max Wavelength for Forming EHP

Thread starter 4220Fox
Start date Dec 9, 2012
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In summary, the maximum wavelength for forming electron-hole pairs (EHP) in Silicon PV cells is approximately 1.1 micrometers due to the indirect bandgap nature of Silicon. This can significantly impact efficiency as longer wavelengths have lower energy and cannot generate as many EHP. However, it is possible to extend the maximum wavelength by using materials with a narrower bandgap, although this comes with a higher cost and more complex manufacturing processes. The thickness of the Silicon layer also plays a role, as thicker layers can absorb more light and allow for longer wavelengths to generate EHP, but can also cause recombination and decrease efficiency. Therefore, there is often a trade-off between the maximum wavelength for forming EHP and efficiency in Silicon PV cells

Dec 9, 2012

4220Fox

Hi, Given that the band-gap of a silicon PV cell is 1.1 eV, what is the maximum wavelength of solar energy (minimum frequency) required forming an electron-hole pair (EHP)?

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Dec 10, 2012

4220Fox

Any idea on Fuel cells from the community on this one, Thank you.

What is the maximum wavelength for forming electron-hole pairs (EHP) in Silicon PV cells?

The maximum wavelength for forming EHP in Silicon PV cells is approximately 1.1 micrometers. This is because Silicon is an indirect bandgap semiconductor, meaning that electrons cannot easily transition between energy bands. As a result, longer wavelengths of light are not able to generate enough energy to form EHP.

How does the maximum wavelength for forming EHP in Silicon PV cells impact efficiency?

The maximum wavelength for forming EHP in Silicon PV cells can significantly impact efficiency. Since longer wavelengths have lower energy, they are not able to generate as many EHP as shorter wavelengths. This means that a significant portion of the incident light is not being converted into electricity, resulting in lower overall efficiency.

Can the maximum wavelength for forming EHP in Silicon PV cells be extended?

Yes, it is possible to extend the maximum wavelength for forming EHP in Silicon PV cells by utilizing materials with a narrower bandgap, such as Gallium Arsenide. This allows for a wider range of wavelengths to generate EHP and can improve the efficiency of the PV cells. However, this also comes with a higher cost and more complex manufacturing processes.

How does the thickness of the Silicon layer impact the maximum wavelength for forming EHP?

The thickness of the Silicon layer can also impact the maximum wavelength for forming EHP. Thicker layers of Silicon absorb more light, allowing for longer wavelengths to generate EHP. However, if the layer is too thick, it can also cause the electrons and holes to recombine before they can be collected, decreasing efficiency. Therefore, the thickness of the Silicon layer must be carefully optimized for maximum efficiency.

Is there a trade-off between the maximum wavelength for forming EHP and efficiency in Silicon PV cells?

Yes, there is often a trade-off between the maximum wavelength for forming EHP and efficiency in Silicon PV cells. As mentioned before, utilizing materials with a narrower bandgap can allow for longer wavelengths to generate EHP, but this comes with a higher cost and more complex manufacturing processes. Additionally, if the Silicon layer is too thick to absorb more light, it can also cause a decrease in efficiency. Finding the optimal balance between these factors is crucial for maximizing the efficiency of Silicon PV cells.