Table of ContentsIntroductionThin-Film Silicon: Beyond Amorphous Silicon?CdTe: Beyond First Solar and Implications for Materials Suppliers?CIGS: If Not Now, When?BIPV, TFPV, Flexibility and MaterialsConclusionAbout Nanomarkets
Despite the end of the silicon shortage and the economic problems that beset much of the developed world, and the construction industry in particular, the prospects for thin-film photovoltaics (TFPV) still look quite good. First Solar, which dominates the CdTe sector has survived the downturn quite nicely. And the CIGS sector with all the advantages of conventional solar panels is still keeping that promise alive. It is anticipated that TFPV can offer flexible PV products for building-integrated PV (BIPV) applications and is more preferred when compared to conventional PV.
Thin-Film Silicon: Beyond Amorphous Silicon?
Thin-film silicon material has an inherent weight and flexibility advantage over conventional silicon because of the materials that it uses. This is, obviously, very well understood by materials suppliers, but we note that the rise of thin- film BIPV, which may put flexibility at a premium, is very good news for materials firms selling into this space in that it means greater volumes of thin-film products sold.
But where we see a genuine value-added opportunity for materials suppliers in the thin-film silicon space is by offering new kinds of silicon. Traditional single and dual-junction amorphous silicon cells have reached maturity and are at the point of incremental cost cutting. Current cells remain attractive for applications that require a low cost and do not require high conversion efficiencies of 8 to 10 %.
From a materials perspective, the excitement here is in the area of microcrystalline, nanocrystalline and advanced heterostructures (nanorods, etc.) which may give a path to 12-18 % efficiency while reusing much of the same knowledge base and manufacturing infrastructure, hence providing a potential path to greater efficiency with little increased cost. The new structures based on microcrystalline or nanocrystalline silicon also are much less susceptible or immune to the loss of efficiency from the Staebler-Wronski effect that plagues true amorphous cells.
According to NanoMarkets, combinations of thin-film silicon and c-Si are already common in the form of Sanyo's Heterojunction with Intrinsic Thin Layer (HIT) cell and a first step towards using nanosilicon may be a hybrid approach of this kind. Thus, Innovalight's printed nanocrystalline silicon PV material will be used commercially in this way on top of a c-Si wafer, in order to launch with a premium product instead of a low-performance pure nanocrystalline silicon-only cell that is not likely to be favorably received in the marketplace.
CdTe: Beyond First Solar and its Implication for Materials Suppliers?
While NanoMarkets concentrates on materials suppliers in this report, not panel makers, it is impossible not to mention First Solar in any kind of discussion about CdTe. First Solar dominates the CdTe space and the low cost structure of First Solar's manufacturing is quite popular. Because of this dominance, the CdTe space has brought about standardization of the materials used for CdTe PV in a manner not seen in the other materials-defined sectors of the PV industry.
One of the reasons that First Solar is so strong in this space is that other CdTe suppliers of the past have had management problems and have had issues that are not any indication on how things will pan out in the future. We note there are now several firms active in the CdTe space deserve to be taken seriously. Several possible competitors for First Solar on the horizon are Prime Star Solar (backed by GE), Abound Solar (formerly AVA), Q-cells/Calyxo-USA.
But since the newer companies are using different deposition techniques to First Solar, their materials requirements are likely to be somewhat different from those of First Solar, allowing the entry of newer suppliers, perhaps.
CIGS: If Not Now, When?
Presently CIGS has only a handful of companies producing CIGS PV modules in the tens of megawatts. However, the CIGS space got a boost in mid-2010 into the film PV arena with a CIGS based solution. The entry of TSMC addresses the capitalization issues that have plagued the many small players in the field.
The moisture sensitivity inherent in the CIGS material, however, is definitely a materials issue and at the present time requires a hermetic seal from the environment. There does, however, seem to be progress in this area and significant opportunities to make further progress too. Encapsulation standards have been tough to achieve, but recently some of the flexible module manufacturers who have partnered with companies such as 3M and have reported success with flexible CIGS modules with durability similar to flexible a-Si PV modules. The encapsulation issues are stricter but not unlike a-Si panels which had module sealing issues when they were initially introduced.
BIPV, TFPV, Flexibility and Materials
Encapsulation opportunities are rapidly increasing in the BIPV space. Some BIPV applications such as rigid roofing tiles and facades can lend themselves to both c-Si and TFPV. However, there is an increasing market for flexible BIPV products that only TFPV (and OPV/DSC) can capture. Flexible roofing shingles and flexible laminates that are applied to conventional building materials will not work with c-Si PV as it is too rigid and brittle. Also often in need of flexible PV are tents, portable chargers and soft briefcases which incorporate PV modules, although this is a very special market.
These flexible applications are among the major areas of interest to material suppliers because of the unique material requirements. Flexible substrates are needed in such applications and an interesting variety of such products are now being introduced into the market, from sheet metal to high-performance plastic sheeting to so-called flexible glass. The greatest opportunity, however, we suspect will be found in the flexible encapsulation market, since, at present, high-performance flexible encapsulation is very costly, and affordable encapsulation can be a challenge. A breakthrough in this area, NanoMarkets believes will prove a key enabling technology for flexible PV products.
Hence, in spite of the many negatives that have accumulated for the solar industry as a whole in the past two years, NanoMarkets believes that there continues to be significant opportunities for materials suppliers coming out of the TFPV sector. In addition to the ones that stem directly from the core absorber material issues, there are important challenges in the encapsulation and substrate space that will lead to new opportunities for firms that one do not usually think of as being in the PV industry. There are also opportunities in the electrode space, where, panel makers will like to get rid of expensive silver and ITO if it didn't mean sacrificing performance as well.
NanoMarkets is a leading provider of market research and industry analysis of opportunities within advanced materials and emerging energy and electronics markets. Since the firm’s founding, NanoMarkets has published over one hundred comprehensive research reports on emerging technology markets. Topics covered have included OLED displays, lighting and materials, thin-film electronics, conductive inks, transparent conductors, renewable energy, printed electronics and other promising technologies. Our client roster is a who’s who of companies in specialty chemicals, materials, electronics applications and manufacturing.
This information has been sourced, reviewed and adapted from materials provided by NanoMarkets.
For more information on this source, please visit NanoMarkets.