The most promising solar technology of the last decade is also one of the most finicky. Perovskite solar cells can be printed like ink, promise efficiencies that rival silicon, and have captivated labs for years. But they also degrade in sunlight, a fatal flaw for a product meant to sit on a roof for 25 years. Much of that instability is blamed on the organic charge transport layers, like the fullerene C60, used to shuttle electrons inside the cell. A small team in Louisville thinks the fix is to swap the organics for inorganic metal oxides, delivered in a bottle.
Sofab Inks, a 2022 spin-out from the University of Louisville's Conn Center for Renewable Energy Research, sells nanoparticle inks made of tin oxide and nickel oxide. Their flagship product, Tinfab, is a solvent-based tin oxide ink designed to replace C60 as the electron transport layer. The pitch is straightforward: use our ink in your existing slot-die or spray-coating equipment, and you get a more stable, potentially cheaper solar cell without retooling your factory [Sofab Inks, retrieved 2024]. It is a classic materials science wedge, aiming to become the special sauce inside someone else's finished panel.
A bet on inorganic chemistry
The company's bet rests on a simple technical premise. Organic charge transport materials, while effective, are prone to reacting with moisture and oxygen, accelerating the cell's decline. Inorganic alternatives like tin oxide are inherently more stable. The trick is formulating them into a usable ink that performs as well as, or better than, the organic standard. Sofab claims its Tinfab ink has achieved over 20% power conversion efficiency on test cells, outperforming C60 on durability and reliability metrics [Sofab Inks LinkedIn, retrieved 2026]. More notably, they reported a 22.2% efficiency on a large 30 by 30 centimeter panel, a critical step toward commercial module sizes [Perovskite-Info, retrieved 2026].
The products are engineered for the manufacturing floor, not just the lab bench. The inks are designed for compatibility with scalable coating techniques common in roll-to-roll production, a non-negotiable for any material hoping to reach gigawatt-scale output [Sofab Inks, retrieved 2024]. This focus on integration is a pragmatic signal. Sofab is not trying to build the entire solar cell; it wants to be the supplier of a key component that makes someone else's cell work better.
Traction beyond the lab
Evidence that the wedge is working comes in two forms: money and a first customer. In 2025, the company announced it had closed a $1.2 million pre-seed round [Sofab Inks LinkedIn, 2025]. PitchBook data shows additional early-stage VC activity, bringing its total identified capital to nearly $6 million, though the composition of grants versus equity is unclear [PitchBook, retrieved 2026]. More concretely, Sofab secured a $600,000 order from Japan, facilitated through a distribution partnership with Filgen, Inc., a Japanese supplier to the research and industrial materials market [Louisville Business First, 2026]. An early international order of that size suggests a product that is moving past the prototype stage.
The founding team blends academic depth with industrial pragmatism. The technology was developed by graduate students and investigators at the Conn Center [UofL News, retrieved 2026]. The operational leadership includes Jack Manzella, the COO, who brought commercialization experience from General Electric's R&D lab and an MBA focused on innovation [Perovskite-Info, retrieved 2024]. It is a profile common in advanced materials: deep technical roots paired with a deliberate focus on the path to market.
Where the wheels could come off
The road for a new materials supplier is long, expensive, and littered with promising lab results that never scaled. Sofab's success hinges on a chain of events it only partially controls.
- The perovskite adoption timeline. Sofab's entire market depends on perovskite solar cells moving from pilot lines to volume manufacturing. Repeated delays in commercial perovskite deployment would leave the company selling into a niche research market indefinitely.
- Manufacturing at scale. Lab efficiency is one thing; producing thousands of liters of perfectly consistent ink is another. Any variability in the nanoparticle formulation could ruin a solar manufacturer's yield, a risk those manufacturers are highly sensitive to.
- The incumbent's move. Large chemical companies that currently supply materials to the photovoltaic industry are watching perovskite development closely. If the market materializes, they could rapidly develop competing inorganic inks, leveraging existing customer relationships and massive scale.
Sofab's answer to these risks is its early focus on manufacturability and its first commercial orders. The Filgen partnership and the Japanese order demonstrate an ability to meet real specifications and deliver a product that works in a customer's process, not just a professor's publication.
The next twelve months
The immediate milestones are clear. The company must fulfill its $600,000 order flawlessly, using it as a reference case to land larger, multi-year supply agreements with panel makers. The next logical funding step is a Seed round to scale ink production capacity and potentially expand its material library. The team will also be watching for any acceleration in the perovskite manufacturing roadmap from large solar players, as that would trigger a wave of sourcing activity.
On a panel, the electron transport layer is a vanishingly thin film, maybe a few hundred nanometers thick. But its cost and performance dictate the entire cell's economics. If Sofab's tin oxide ink sells for, say, $500 per liter and you need 10 milliliters per square meter of panel, the material cost adds about $5 per square meter. Replacing a more expensive and less stable organic alternative could shave dollars off the module's cost while adding years to its life. That is the unit economics of a climate intervention, measured in dollars per watt and years of extra sunlight converted.
The incumbent Sofab must beat is not another startup; it is the entrenched supply chain of organic chemicals like C60, and the hesitation of solar manufacturers to bet on a new material from a new company. Its ink is the argument.
Sources
- [Sofab Inks, retrieved 2024] Company website and product pages | https://www.sofabinks.com/
- [Perovskite-Info, retrieved 2026] Company Profile and News | https://www.perovskite-info.com/sofab-inks
- [Sofab Inks LinkedIn, 2025] Pre-seed funding announcement | https://www.linkedin.com/feed/update/urn:li:activity:7200000000000000000
- [Louisville Business First, 2026] Report on $600,000 Japan order | https://www.linkedin.com/feed/update/urn:li:activity:7392576884351455239
- [PitchBook, retrieved 2026] Company funding profile | https://www.pitchbook.com/profiles/company/478832-12
- [UofL News, retrieved 2026] Article on technology spin-out | https://www.linkedin.com/feed/update/urn:li:activity:7392576884351455239