Im looking to know the main difference of using QDs and QWs in a solar cell, and when we can use QDs or QWs
Quantum dots are small spherical nanoparticles made of semiconductor materials, in which the band gap can be tuned by the size. The larger the diameter of the quantum dots, the smaller the bandgap. We can convert more light to electricity by using a multi-junction of quantum dots.
Quantum well solar cells however mainly discuss about structure. Quantum well is a semiconductor with small bandgap which normally takes place between two relatively wide bandgap semiconductors. This well confines charge carriers to move in 2-dimensions rather than 3 dimensions. It seems that CPV would be the beneficiary of this structure as it easily collect and convert quantized charge carriers into the electricity.
Tuning the band gap is according to the size of the quantum dot and also according to the shape of the nanoparticls.
quantum well present the defect from not absorbing incident light and a grating is requested to change their polarization
QD (epitaxially grown) suffer from a low density (few 1011cm-2) wich make their absorption low, but on the other hand they do not require a grating
- Badges
- Science topic