PV Panels Nate Trachimowicz And Evan Graves

How panels work Silicon is doped with different chemicals Providing the desired properties of the resulting compounds Based on valence electrons One compound or side, is made to be electro- negative (N-type) The other side, being electro-positive (P-type) N-type P-type

N-Type: Semiconductors with an excess of electrons P-Type: Semiconductors with an absence of electrons

The Electrons (remember having 4, is stable)

Making Electron Pairs Load N-side Extra P-side Holes

Light Band Gap Electricity Each element has a band gap: The difference in energy between the valence band (electron bound to an atom) and the conduction band (electron free to move between atoms). Measured in electron volts, eV Metals have a low band gap, electrons flow easy Each wavelength of light has an associated energy Silicon band gap is 1.1 eV which peaks in the infrared region (980 nm ) Different elements and materials provide a spectrum of options to absorb the suns energy.

Thin-Film Materials for High Power-to-Weight-Ratio Space Photovoltaic Arrays copper, indium, and sulfur, or copper, indium, gallium, and selenium CuInSe2/CuInS2/CuGaSe2 Decomposition of single-source precursor to produce CuInS2.

Higher efficiency tricks The foundation of the new UNI-SOLAR PVL is the Triple Junction silicon solar cell unique to UNI- SOLAR. Each cell is composed of three semiconductor junctions stacked on top of each other. This spectrum splitting capability is the key to higher efficiency.

Higher efficiency tricks When a photon excites an electron, or kicks it. It will probably fall back into orbit losing energy as heat. This is known as recombination. The trick to constructing high efficiency solar cells lies in minimizing recombination.

Price Comparison, thin film ProductPrice$/W Unisolar PVL-31T roof laminate Unisolar PVL-116T roof laminate Shell ST Shell ST

Good sites /intro.htm /intro.htm html html Eg.r.html Eg.r.html