Solar cells use the element silicon as a semiconductor. Silicon is a great material for allowing the flow of electrons (which we know as electricity) because of its atomic arrangement. Silicon's outer electron layer has four electrons, but there's room for eight. This means that pure silicon is very stable -- the atoms share their electrons and fit together nicely. But adding impurities (specifically boron and phosphorus) to the silicon creates an imbalance.
Phosphorus has five electrons to share, so pairing up with silicon means that it has one to spare. This spare electron could easily be knocked loose. Here's where the sunlight comes in. Sunlight is composed of tiny packets of energy called photons. Depending on their wavelength, photons carry enough energy to knock free electrons loose from their orbit. This is called the photoelectric effect, and it creates a negative charge. Simply knocking electrons loose wouldn't create electricity, though. That effect comes from the boron added to the silicon.
Boron shares three electrons, which leaves a gap when added to silicon. Remember that silicon likes to connect to four electrons. This means one less boron electron, which allows the positively charged nucleus to dominate. This domination creates the positive charge. The natural tendency to seek equilibrium means that the open bond at the boron/silicon site will attract the free electron left over by the phosphorus/silicon bond. This creates the flow of electrons -- otherwise known as an electrical field. By adding an external load (in the case of the VizorSUN, a rechargeable battery), this electron flow is stored for use.
The other component of the VizorSUN is Bluetooth. Bluetooth wireless technology uses radio waves to allow one device to communicate with another. With all Bluetooth-enabled wireless devices operating on the same frequency -- around 2.4 megahertz -- and with communication between these devices transpiring automatically whenever one comes in range with another, things could get garbled. But Bluetooth emits radio transmissions at extremely low power, between one to 10 milliwatts (one-thousandth to one-tenth of a watt) [source: Northstar]. Even when a multitude of wireless devices are within close proximity to one another, garbled and rotating transmissions are prevented by each device operating on several different frequencies within a single second. This means the changes of two operating on the same frequency unintentionally are decreased.
The VizorSUN marries solar and Bluetooth technologies into a coherent whole, with the solar cells providing an electrical charge to the battery, which, in turn powers the Bluetooth radio, the digital display, speaker, microphone, volume setting and the one-touch call technology.
Find out about more benefits of the VizorSUN on the next page.