Place any of a variety of photovoltaic materials in direct sun light and they immediately begin creating electricity. Their nature is to convert the sun’s photon’s energy into free electrical power – here’s how.

By the way, the term Photovoltaics connotes light that produces electricity. Sunlight is made up of many different frequencies. For instance, placing a prism in sunlight will reveal many different colors.

When light enters the glass solar energy cells, it slows down. This is due to the electric charge in the glass which delays the light waves by interacting with the wave’s electric and magnetic fields. Higher light frequencies increase interaction with the material; more interaction reduces the speed of the light as it travels through the glass.

Hence high frequency violet slows more than the low frequency red as both enter and travel through the glass.

Due to this deceleration influence, when light intersects a surface, it bends at an angle in relation to the speed of the different color bands. Light wave widths vary with frequency as evidenced by part of the wave arriving at the surface before the other parts of the wave. The higher frequency (violet) portion of the wave arrives first but slows more; while the lower frequency (red) arrives last but is affected less.

Accordingly, the whole wave bends as it travels into and through the glass. Each color bends more or less then the others as they follow different paths through the glass. Upon exiting the glass through another surface, the process is reversed. The light speeds up and those at the higher frequencies (violets) bend more the slower reds.

Sunlight is energy. As it’s absorbed and transferred into the semiconductor material some of the material’s electrons are knocked loose and begin flowing as current.

However because IR’s (red’s) produce heat, they make little electricity and restrict the photovoltaic materials efficiency.

Ultra violets purples blues greens and yellows produce the most power therefore color band filtering is used. Ideally, the lower the band gap the more efficient the device is.

Note that most of the glass, or plastics used in photovoltaic cells is either blue or green. Therefore, colored solar energy cells provide controlled filtering for the solar photon energy absorbed by the semiconductor, and reduce IR interaction, thus heat. This covering material also allows sunlight to enter but blocks reflections.

Basically, sunlight photons entering solar energy cells knock some of the electrons free of their natural orbit about the nucleus. Such electrons move to a higher state of energy and begin to flow as current in the electrical circuit in the solar panels.

A good way to picture this is with the example of a cue ball breaking a rack of billiard balls. Most of the balls remain in the general vicinity. However, a few get knocked free; if the player is lucky maybe one or two go in a pocket. Consider each ball entering a pocket – electrical current.

The photovoltaic materials used in solar energy cells have different spectral responses to ordinary sunlight, and exhibit a varying sensitivity with respect to the absorption of photons at given wavelengths. Great numbers of these are grouped together in solar pv panels and are responsible for creating electricity. Each one producing

The photovoltaic materials used in individual cells respond to different colors corresponding to how they are manufactured. Hence solar cell electricity is produced for their owners.

On the other hand, a certain amount of surplus photon energy is transformed into heat rather than into electrical energy. In addition to that, there are optical losses, such as the shadowing of the cell surface through contact with the glass surface or reflection of incoming rays on the cell surface.

The materials used to make PV cells are semi conducting elements. The most commonly used is silicon, other materials used include gallium arsenide, copper indium diselenide and cadmium telluride.

Since each material has a different band gap, each is “tuned” to different wavelengths, or photons of different energies. The average output is 0.5 volts @ from1 to 5 amps.

That’s the big picture, but there’s a lot more. Anyway, I’m sure you can see why so many individual PV cells are required in a solar panel to achieve usable levels of energy.

Now you know how photovoltaic materials convert sunlight to electrical energy.