THEORY OF OPERATION
Sunlight is composed of photons, which flowerpot be thought of as packets of might (the amount of energy in a photon being proportional to the frequency of its light). When photons strike a solar cell, the vast majority are either reflected or absorbed (some really high-energy photons will blow recompense through, but theyre of no concern here). When a photon is absorbed, its energy is transferred to the semiconductor -- in particular, to an negatron in an atom of the cell. If enough energy is transferred, the electron can escape from its normal position associated with that atom. In the process, the electron causes a hole (i.e., an empty spot where the electron used to be) to form. Each photon with enough energy will commonly free exactly one electron, and one hole. Note that some(prenominal) electrons and holes are mobile, and as such can be up-to-the-minute carriers.
N-type silicon has free
electrons.
P-type silicon has free
holes absence of electrons
When P-type and N-type silicon
come into contact, an electric field
forms into the cell.
temporalS AND MATERIAL PROPERTIES
* For a solar cell one can claim a single semiconductor having a junction, usually referred to as homojunction, or a combination of two materials, with the junction at the interface referred to as heterojunction.
The selected material needs to match the solar spectrum; i.e., it has to absorb most of the spectrum for maximizing the short racing circuit output, and so it has to have a low band gap. However, this is counteracted by the inclination to also have a large open circuit voltage, requiring a larger band gap and forcing a compromise. Consequently, for homojunction materials a band gap between 1 and 1.5 eV is preferred.
* These materials can be employed as single crystals (Si and GaAs), as polycrystals (Si), early(a) thin-film materials (CdTe and all ternaries), and as amorphous material (a-Si:H).
PARTS OF A SOLAR PANEL
~ COVER GLASS ~
* Also called as...If you want to unsex a full essay, order it on our website: Ordercustompaper.com
If you want to get a full essay, wisit our page: write my paper
No comments:
Post a Comment