There are a lot of thin film companies -- maybe 80 to 90 firms working on various aspects of the technology. I’ve limited the entries on this list to private firms funded by Venture Capital and Private Equity. No public firms, no subsidiaries of public firms.

The thin-film sector is by far the leading recipient of VC funds in solar (and the entire renewable energy field). That’s because: 1.) VCs love multi-billion dollar industries like solar with steady 30 percent plus per year growth; 2.) The potential exists for thin film to disrupt the dominant wafered-silicon technology as well as create and enable new markets; and, 3.) VCs are looking to replicate the success of First Solar and its thin-film IPO.

Out of the 35 or so private thin-film firms, only a few will survive and even fewer will make it to the VC goal line -- an IPO or acquisition. It might be one of the well-financed CIGS firms like Nanoslar or Solyndra. Then again, one of the stealth firms now being gestated might be the black swan that changes the economics and scale of PV. Here’s the list parsed by thin-film material -- thin-film silicon, CdTe and CIGS.

Thin-Film Silicon and variations thereof

Ampulse: Ampulse is funded with more than $1 million from Battelle Ventures and the DOE for “film silicon" and is seeking $10 million in its next round. Using “Hot-Wire CVD," the company coats a metal substrate with a thin-layer of silicon, which then crystallizes. Ampulse is targeting a 15 percent conversion rate for its cells and is working with NREL and ORNL.

AOS Solar: AOS claims to combine c-Si PV efficiency with high-throughput thin film manufacturing economics. The company has received angel funding and a $500,000 DOE grant.

APSTL: APSTL deposits a thin layer of crystalline silicon on a metallic substrate, claiming the approach is driven by an understanding of imperfections in silicon and its effect on electron transport, as well as “the effect of deposition processes and crystal growth conditions on the creation of various defects."

CSG Solar: Crystalline Silicon on Glass technology firm, CSG raised ~$35 million from Apax Partners and Good Energies in 2005, who joined existing investors Q-Cells, REC and IBG. Its crystalline silicon layer is less than 2um in thickness. Press releases from 2007 claim that the company is in 24/7 production in Germany.

EPV SOLAR: Privately owned EPV’s 30,000 square foot, 20-MW facility in New Jersey is producing and shipping thin-film a-Si solar modules. There is another facility in Germany that brings total capacity to about 50 MW. EPV recently announced the closing of $78 million of convertible senior secured notes.

FlexCell: a-Si deposited on flexible plastic film via a very high frequency (VHF) plasma deposition technique. FlexCell received $9 million from Q-Cells in 2006.

HelioSphera (a.k.a. Next Solar): Greek firm readying 2009 production of “micromorph tandem" thin-film PV panels with an annual capacity of 60 MW, using Oerlikon’s micromorph technology at 3um thickness. The firm received investment from Plainfield Asset Management and Sciens International.

NanoPV Corp: Early stage “Thin-film nanocrystalline silicon" targeting 8.5 percent efficiency large-area modules.

Optisolar (a.k.a. Gen3 Solar): Optisolar is a secretive a-Si manufacturer with more (maybe much more) than $200 million in PE funding and a 550-MW PPA from renewables-friendly Northern California utility PG&E.

Sencera: Funded by The Quercus Trust and Equinox Securities, Sencera develops tandem amorphous/microcrystalline solar cells with target conversion efficiencies greater than 10 percent courtesy of their plasma-enhanced chemical vapor deposition (PECVD) technology They recently achieved 7 percent conversion efficiency in lab tests, which triggered an additional $5.2 million investment and are in the process of raising ~$36 million in capital to build a 38MW module factory in Charlotte, NC.

Sierra Solar Power: $7.1 million from GSR Ventures and Mayfield China for thin film silicon.

Signet Solar: Signet builds a-Si panels using Applied Materials’ SunFab line, producing large panels for utility scale deployment - 5.7 square meters in area. Their first production line was established in Germamy. Signet completed a first tranche of a Series A round of $5 to $10 million from undisclosed angel investors in 2007 and is working with investors in India and abroad to raise massive capital for its planned capacity expansion.

SkyPoint Solar: A thin film solar panel manufacturing firm, launched with seed capital from its founding management team, including John Tuttle, the former CEO of troubled CIGS solar manufacturer DayStar.  Their technology is based on amorphous / microcrystalline silicon materials and they look to deploy their product in Skypoint-owned and operated solar power parks, both domestically and internationally. InfusionCapital is involved in their financing.

Soltaix: Funded by the DOE, Solataix is working on nano-silicon, high-efficiency, thin-film, crystalline solar cells.

Xunlight (a.k.a. MWOE): Xunlight is a spin-off from the University of Toledo developing thin-film silicon PV on flexible substrates. The thin-film silicon is deposited via PECVD while a magnetron sputter deposition system is used to deposit the non-semiconductor layers - Al, Ag, ZnO and ITO, required for the cells. They raised $40 million in several rounds from Rabo, Emerald Technology Ventures, NGP Energy Technology Partners, and Trident Capital in addition to significant R&D funding from the DOE, AFRL, NIST and state government sources.

CdTe Startups

AVA Solar: AVA Solar closed its seed round in early 2007 and its first VC round in June 2007, led by The Invus Group. AVA Solar then raised $104 million in a funding round led by DCM with Technology Partners, GLG Partners, et al. in order complete its 200MW CdTe thin film plant in Longmont, Colorado. Manufacturing method is “Air-to-Vacuum-to-Air (AVA)" belt.

Bloo Solar: Formerly known as Q1 NanoSystems, Bloo Solar has IP from UC Davis and builds nano-structured “bristles" layered with CdTe as the PV material although other materials can be used. The bristled substrate provides greater surface area and acceptance angle. It has received $100,000 from an NSF grant and are looking for their first VC round.

Canrom: Thin-film CdTe technology ready to start production but lacking working capital. Funded, at one point, by the New York State Energy Research and Development Authority (NYSERDA).

Golden Photon: Originally called Photon Energy, Golden Photon was acquired by ACX Technologies of Golden, CO. Early CdTe developer with the DOE and NREL, although currently inactive.

NewCyte: An array of vertically-aligned carbon nanotubes form 3D solar cells from researchers at Georgia Tech. The research is sponsored by the Air Force Office of Scientific Research and the AFRL, and Intellectual Property Partners. MBE is used to coat the nanotubes with CdTe and CdS which act as the p-type and n-type PV layers.

PrimeStar Solar: PrimeStar was formed in June 2006 with funding of $6.2 million from individuals and a global investment bank. In 2007, GE Energy took a minority equity position in PrimeStar Solar, raising its stake to become a majority shareholder in June 2008. With CdTe technology licensed from NREL, their product will be a 60 cm x 120 cm frameless glass-glass PV module for use in large-scale grid connected installations.

Solar Fields: CdTe developer bought by Q-Cells in 2007 and merged with Q-Cells’ Calyxo subsidiary to form Calyxo USA.

Sunovia: Working with EPIR, in which it has a significant equity position, Sunovia is attempting to develop CdTe on Si, for a multijunction solar cell with initial applications in CPV. Sunovia received $12 million in funding from an undisclosed source in 2008.

Xunlight 26 Solar:  Spun-out from VC funded Xunlight in April 2008 to develop flexible solar cells based on CdTe and other II-VI compound semiconductors.  Xunlight raised $40M in several rounds from Rabo, Emerald Technology Ventures, NGP Energy Technology Partners, and Trident Capital, et al. to develop thin-film silicon PV on flexible substrates.

Zia Watt Solar: Some past activity in CdTe PV.

CIGS

Global Solar Energy: Privately held Global Solar Energy is a producer of thin-film photovoltaic CIGS solar cellsfor use in solar panels as well as in flexible, portable solar chargers. They recently installed a 750-kW system at their manufacturing site in Tucson, Ariz. In 2006, shares were sold for $16 to an anonymous European VC investor and to Solon, a German producer of PV modules.

HelioVolt: HelioVolt’s 20-MW CIGS thin-film solar production plant will be financed by the firm’s B round which closed at $101 million in 2007. Investors in the B Round include NEA, Paladin Capital Group, Masdar Clean Tech Fund, Solúcar Energia, Morgan Stanley Principal Investments, Sunton United Energy, Yellowstone Capital, Sequel Venture Partners, Noventi Ventures and Passport Capital. Its manufacturing process is modeled after an electroplating technique and the firm claims it can “print" on glass, steel, metal, composites and some polymers for use in BIPV and other PV applications.

ISET:  Since 1985, privately held ISET has received ~$15M in funding from federal, state agencies, and private corporations. ISET has developed a non-vacuum approach to the deposition of the CIGS absorber layer using water-based inks made from nanoparticles of copper, indium and gallium oxides as precursor materials.  

Miasolé: CIGS solar vendor Miasolé’s first three rounds of VC from KPCB, Vantage Point Venture Partners, Garage Technology Ventures, and Firelake Capital Management totaled ~$101 million. In July 2008, the firm announced the closing of a ~$200 million round. Their product is produced on a flexible substrate. Although they have made progress in their device efficiency, there have been setbacks in personnel and technology.

Nanosolar: CIGS thin-film solar manufacturer Nanosolar is one of the largest recipients of VC and strategic funding in the solar startup world with more than $500 million raised from Benchmark Capital, Firelake Capital, First Ventury, GLG Partners, Grazia Equity, LGT Capital Group, Mitsui & Co Ltd., Mohr Davidow Ventures, OnPoint Technologies, SAC Capital, Scoll Foundation, Standford University, Swiss Re, AES, the Carlyle Group, EDF, Energy Capital Partners, et al. The firm claims to have shipped its first commercial panels in December 2007. Nanosolar’s innovations include a solar ink deposited in a printing industry-like roll-to-roll process, a conductive foil substrate, and a low cost top electrode.

Odersun: Odersun, developing flexible thin-film CIS solar cells, closed a $60 million B round in early 2008 from Virgin Green Fund, PCG Clean Energy & Technology Fund, AGF Private Equity, Doughty Hanson Technology Ventures, and Advanced Technology & Materials. It also received ~$30 million in German government funding. Their roll-to-roll manufacturing process uses long reels of copper tape and can be packaged in flexible or rigid formats.

SoloPower: SoloPower builds CIGS-based PV cells using something akin to electroplating. SoloPower claims to be able to add controlled amounts of gallium and/or sulfur into the absorber layer to adjust its energy gap, allowing higher voltage, better carrier collection, and higher conversion efficiency. Their products can be packaged into rigid or flexible structures. SoloPower is one of the very well funded CIGS firms with more than $230 million from Crosslink Capital, Firsthand Capital Management, Convexa Capital, Alf Bjørseth, co-founder of REC, et al.

Solyndra: Their 2007 funding of ~$79 million from CMEA and RedPoint Ventures was followed by hundreds of millions in investment from Argonaut Ventures, Rockport Capital, USVP, Masdar Clean Tech Fund, Madrone Capital (The Walton family fund which also funded First Solar). They produce radically innovative CIGS on glass cylinders for rooftop deployment and have announced more than $1.2 billion in customer contracts. The company also anticipates access to a DOE loan program.

Sulfurcell Solartechnik: Sulfurcell has been manufacturing and developing thin-film solar modules based on chalcopyrite-type semiconductors on glass (CIS/CIGSe) since 2003. They received $10 million from Masdar Fund, Vattenfall Europe, Ventegis Capital, et al. in 2007 and $134 million from Intel Capital, Climate Change Capital Private Equity, AIG, Demeter Partners, Zouk Ventures, and BankInvest in Q3 2008.

Telio Solar: Korean-headquartered CIGS startup.

Check out the previous installments of this series: