Materials used in crystalline silicon and thin-film solar photovoltaic (PV) modules will surge over the next five years to nearly $42 billion worth of sales, according to AEI Consulting. That's even assuming this year is flat due to the impact of policy changes in major PV markets in Europe.

AEI's report covers the production processes and supply chain for solar cell manufacturing, including silicon, slurries, gases, wet chemicals, precursors, dopants, and other materials.

The group finds, for example, that of the $19.7 billion worth of solar PV materials sold in 2011, polysilicon made up 41 percent of that; next was glass, ethylene vinyl acetate (EVA) films, and backsheets (16 percent), saw wires and slurries (12 percent), metallic pastes (11 percent), various chemicals (9 percent) and other materials in the balance (11 percent). Silicon's percentage of that grouping, though, is seen sinking to just 16 percent by 2016, as solar manufacturers adopt new ways to reduce their usage of the material to start with (kerfless wafering and implants, a la Twin Creeks, Ampulse, SiGen and others) or simply improve their methods of processing it, with diamond wire saws. Increasing cell efficiency also will lead to more technology improvements, from improved texturization to double printing, new selective emitter schemes, n-type silicon, plating technologies, passivation layers, etc.

Makers of thin-film solar PV modules also are pressing ahead to improve efficiencies and reduce materials costs. Technology upgrades include improved plasma deposition, buffer layer designs, and antireflective layers, and laser patterning. Even more advancements are seen with nanocrystalline silicon oxide doped layers, replacing the cadmium sulfide (Cds) buffer layer with a more transparent material (zinc oxide or ZnO), and adopting close spaced sublimation (CSS) deposition for CdTe cells.

PV cell and module chemical and material demand, in US $ millions. (Source: AEI Consulting)