PVS Skylighting
How PV glass skylights work, this paper explains it all      

In the last few years, from a socio-economic viewpoint, photovoltaic energy has awoken a growing interest; solar radiation alone is sufficient to generate a clean and inexhaustible form of electricity.  When used in glass skylights, users could benefit from the tax and performance benefits.

At its simplest the photovoltaic effect could be defined as the generation of energy from light.  In more scientific terms certain materials have properties which generate a photo-voltage when they are illuminated.     If the material is adequately connected to an external circuit the difference in potential is able to circulate a current producing useful force.

Silicon is noted for its excellence as a photovoltaic material, equally in a crystalline cellular configuration….mono-multi as in thin photovoltaic film,  PV glass reaches efficiency levels of between 7 and 18% on a regular basis.

Similarly, scientific activity in recent years has permitted the consolidation of new materials such as Savannah Skylights heterojuctions of III-V semiconductors (InP/GaAs/Ge) or CIS/CIGS (CuInGaSe2)-based materials leading to an increasing presence in the PV market of this type of new solar cells.  http://www.impactskylights.com/ found that common ground.

In very general terms, the fundamental steps in the conversion of light energy to electrical energy are the following:

Light absorption.
Generation and the migration to the active zone.
Charge separation in the active zone
Transportation of the charge carriers to the electrodes.
Injection of the electrodes from the charge carriers

Solar light is structured in energy particles, named photons. These photons carry different energies, corresponding to the different wave length of the solar spectrum. When the photons fall upon a photovoltaic cell, they can be either reflected, absorbed or they can pass through it. Only  absorbed photons  will generate electricity. When a photon is absorbed the phonon’s energy is transferred to an electron in an atom of an active material. With this new energy the electron is able to escape from its normal position within the atom and form part of a current in an electric circuit.

If the photovoltaic cell only consists of single layer of active material where all processes take place, very low efficiency rate is shown due to inefficient generation of free energy carriers. However, if in the photovoltaic cell is based in different p-n heterojuctions, where each interface act as an active zone, the transportation of charge carriers is improved by the presence of p-type and n-type separated regions. The more complex these heterojuctions are, higher level of efficiency is shown by the photovoltaic system.

Given that the majority of photovoltaic material possesses a relatively low intrinsic conductivity, doping techniques are carried out to facilitate the transportation of the photo-generated charges, such as in the structuring of the cells in heterojuctions. In the case of silicon, the n-type doping (electron transportation) material is usually phosphorous atoms, while the p-type doping (gap transportation) is carried out with boron atoms.

For an efficient extraction of the charges generated by the photovoltaic material and the injection of this into the external system, electrodes of varying complexity are relied upon. These go from Al, Al/Ag, Ag:Mg, or even TOC (semi-transparent conductors such as ITO, o ZnO:Al).  

Finally, the photovoltaic dispositive is encapsulated by a transparent co-polymer in order to protect the systems from atmospheric conditions. It is also laminated between back-sheets of different materials (glass/glass, TEDLAR/glass, PYE/glass etc.) giving rise to the photovoltaic module in its differing configurations.  All to the benefits of PV glass skylights.