PV cells consist of at least 2 semi-conductive materials, one of which has a positive charge and the other, a negative charge. When exposed to sunlight some of the photons are absorbed by the negative semiconductor atoms, which in turn free electrons to flow back to the positive semiconductor. This flow of electrons is called direct current (DC). The individual solar cells are then connected in series strings to build voltage and the strings are connected in parallel to build current. They are then sealed or laminated and placed in a rigid frame. This makes up a photovoltaic (PV) module.
There are three different types of cells:
Mono-crystalline cells : The silicone cells are grown as a single crystal structure and then cut into very thin wavers (usually by laser)
Poly-crystalline cells : The silicone crystal is grown as a multiple crystal structure adhering to each other as one crystal, and then cut into very thin wavers(usually by laser
Amorphous or thin-film type : A deposition process (onto a substrate e.g. glass) is done; creating a layer of silicone crystals that function in a similar way as a crystal grown under extremely high temperatures and pressure . There various types of deposition materials available that may be deposited onto various types of substrate.
These modules or panels are available in various sizes, power outputs, and materials. The power generated can be used for almost any load/appliance that requires electrical power to operate, using the right conversion equipment.
Solar basics 
PV cells consist of at least 2 semi-conductive materials, one of which has a positive charge and the other, a negative charge. When exposed to sunlight some of the photons are absorbed by the negative semiconductor atoms, which in turn free electrons to flow back to the positive semiconductor. This flow of electrons is called direct current (DC). The individual solar cells are then connected in series strings to build voltage and the strings are connected in parallel to build current. They are then sealed or laminated and placed in a rigid frame. This makes up a photovoltaic (PV) module.