In some detail, we will also describe how a solar PV cells use photons created and distributed by the sun to create solar generated electricity. For home solar power, this is the physical process, called the photoelectric effect, makes it possible to create passive solar energy simply from sunlight.

Doping Silicon Cells to Create Home Solar Arrays

Introducing impurities, called dopants, into the silicon making up the solar cell creates the one-way flow of electrons necessary to produce electricity more efficient. Two differently doped silicon wafers are layered together to create this flow. The next section details out the dopants that are often mixed with solar grade silicon to improve efficiencies.

Boron (p-type): Boron is an element containing three electrons within it's atomic structure, unlike silicon, which has four outer electrons. So wherever boron is introduced into the lattice, a hole is created due to the absence of an electron. This hole creates a net positive charge and is filled by a neighboring electron vibrating in to fill the hole there, and leaving a new hole. These positively charged holes move about. Boron doped silicon is also called p-type, because the freely moving charge is positive.

Phosphorus (n-type): Phosphorus atoms contain five electrons rotating around their nucleus. This is one more than silicon. Wherever a phosphorus atom is introduced into the lattice, it has a complete set of 4 electrons to share with its 4 silicon neighbors and a 5th electron with no bond to fill. The fifth external electron rotating around the core of the atom bumps free of the atom and moves throughout the silicon wafers or lattice structure. So the introduction of phosphorus provides an electron that moves within the crystal lattice. This type of doped silicon is called n-type because the freely moving charge is negative.

Solar Cells, Electricity and the P-N Junction: What?

The magical flow direction needed to provide current of positive charge in one direction and negative charge in the opposite is created where these two differently doped silicon wafers are "mashed together" as a diode. The surface where the where n-type silicon meets p-type silicon is called the p/n junction.

An interesting aspect to define, the two materials each containing an opposite charge when placed side-by-side create an electric field where electrons pass back and forth. This simple structure is called a diode; a necessary and critical step in the creation of solar cells for home solar electric generation.

At the p-n junction, the extra phosphorus electron breaks free and wanders until it falls into a hole near a boron atom. Because the phosphorus atom starts out neutral, neither having a negative nor a positive charge due to the loss or addition of an electron, it will have a net positive charge when it looses it's negative electron. Similarly, the boron site, which was electrically neutral, now has one more electron, which makes the net charge at the site negative.

This process continues all along the region between n-type and p-type silicon, with extra phosphorus electrons crossing over to fill boron holes. Creating two areas with opposite atomic charges, this process creates two charges within the silicon PV cell. The result is a flow of electrons from one side to the other and the production of an electric current. The electric field is produced within the silicon wafers at the p-n junction of the diode.

Understanding How Solar Energy Fits into the Mix

We are at the dawn of a solar revolution in the United States. Every aspect of the solar industry is experiencing explosive growth. Triple digit expansion in solar photovoltaic cell manufacturing, to the need for solar sales associates, to the huge demand for solar system installers. Opportunities abound everywhere.

The renting of a solar energy system for your home is a new, attractive twist to the idea of switching to renewable energy. With the adoption of a leasing or rental model for residential solar electric systems, an average homeowner can now go green at home as well as build a part-time, solar energy business.