Materials for Thin-Film, Organic PV $3.8B by 2015
Staff -- Semiconductor International, 2/26/2008 7:57:00 AM
Materials used in thin-film and organic photovoltaics (PV) will reach $3.8B by 2015, according to a new study by NanoMarkets, an industry analyst firm based in Glen Allen, Va. The PV market is becoming a source of opportunity for both traditional electronic chemicals suppliers and innovative materials firms. In addition, innovations at the material level will have a profound impact on the future of PV as a whole.
The report notes that thin-film PV is no longer a niche consumer of electronic materials. By 2015, amorphous silicon PV will use more than $900M in silane gas and other silicon-based materials. A few years ago, producers of crystalline silicon found that conventional PV was a major new business opportunity. Thin-film PV is bringing the same kind of opportunity to the leading suppliers of electronic chemicals.
According to SolarBuzz, another market research company, thin-film PV materials of choice are all strong light absorbers and only need to be about 1 µm thick, so material costs are significantly reduced. The most common materials are amorphous silicon, cadmium telluride (CdTe) and copper indium (gallium) diselenide (CIS or CIGS).
Each of these three is amenable to large-area deposition (on to substrates of about 1 meter dimensions) and, hence, high-volume manufacturing. The thin-film semiconductor layers are deposited onto either coated glass or a stainless steel sheet.
The semiconductor junctions are formed in different ways, either as a p-i-n device in amorphous silicon or as a hetero-junction (e.g., with a thin cadmium sulphide layer) for CdTe and CIS. A transparent conducting oxide layer (such as tin oxide) forms the front electrical contact of the cell, and a metal layer forms the rear contact.
The new NanoMarkets report states that CIGS promises all the advantages of thin-film PV, but with conversion efficiencies almost as high as conventional PV. However, that the ability for CIGS to deliver on this promise will depend on innovative materials firms, according to the report. The CIGS industry is looking for better formulations of selenium that avoid the volatility problems experienced in high-temperature manufacturing processes. CIGS cell construction also makes the choice of materials for the top contacts highly demanding. NanoMarkets believes that such problems will be overcome in the next few years and that by 2015, the CIGS PV sector will consume a total of $1.1B in materials.
In the near future, thin-film materials will provide entirely new directions for PV. Silicon inks will soon be available that will combine the manufacturability advantages of organic PV, but with much higher conversion efficiencies. Slivers of crystalline silicon have been developed that combine the high efficiency of crystalline silicon with the flexibility and ease of fabrication of thin film, and this technology is already being used in a pilot plant. Further off lies the commercialization of inorganic nanocrystals designed to overcome the one electron per solar photon limitation in solar energy conversion. CdSe, CdS and CdTe nanocrystals have all been employed in this way in the lab and hint at a thin-film PV of the future with energy conversion ratios well into the double digits.
The report, titled "Materials Markets for Thin-Film and Organic Photovoltaics," includes eight-year forecasts of thin-film and organic materials broken out by material functionality and chemistry, as well as reviews of the latest research and the corporate strategies of firms active in the sector. PV technologies covered include amorphous silicon, cadmium telluride, CIGS, dye cells and pure organic approaches. Key firms mentioned in the report are Air Liquide, BASF, Dow Corning, Evonik, Indium, Konarka, Linde, Nanosolar, Mitsui Toatsu Chemicals, Nanoco, Plextronics, Praxair, REC, Redlen, Sanyo, Sputtering Materials, Sulfurcell, Umicore and Voltaix.
