The Rise of Perovskite Solar Cells
When US energy policy took a sharp U-turn last year, supporting expensive and polluting energy resources while throttling back on economical solutions like solar, it seemed counterintuitive. Yet, the domestic solar industry continues to out-perform competitors in adding new generating capacity. A fresh turbo-boost is coming from new perovskite solar cell technology, which promises to make solar power even cheaper.
Breakthroughs in Efficiency and Durability
Triple-Junction Cells Achieve New Records
Perovskite was first demonstrated as a promising solar material in 2009, but durability issues held it back. Recent commercial-level workarounds include pairing perovskite with silicon in tandem cells. Researchers have also ventured into triple-junction solar cells. Last year, a team in Australia achieved a 23.3% conversion efficiency for a triple-junction cell measuring about 2.5 square inches, composed of two types of perovskite and silicon. They also reported a 27.06% efficiency for a smaller version measuring 1 square centimeter.
Graphene and SAMs Boost Stability
At Germany’s HZB (Helmholtz-Zentrum Berlin für Materialien und Energie), researchers combined graphene with perovskite, leveraging self-assembled monolayers (SAMs). They replaced the commonly used conductive polymer PEDOT:PSS with a graphene-based formula to improve durability. Their findings, published in the peer-reviewed journal Joule, demonstrate the immense potential of SAM-based perovskite solar cells and bring the technology closer to industrial readiness.
Lighter Solar Panels for Wider Adoption
Power Roll and Queen Mary University Partnership
In the UK, Innovate UK supported a partnership between Queen Mary University of London and startup Power Roll to address the gap in lightweight solar panels. Almost 30% of commercial rooftops worldwide cannot support the weight of traditional silicon panels, which explains why only 2% of buildings globally have solar panels—despite the sun providing enough energy in an hour to power the world for a year. The UK alone has an estimated 12 billion square meters of rooftop incapable of supporting conventional panels but suitable for lighter perovskite technology.
Eliminating Expensive Materials
Power Roll’s perovskite formula eliminates the commonly used but expensive material (likely spiro-OMeTAD). The company launched its first trial outside Europe earlier this year in partnership with Tokyo Gas, leveraging Tokyo Gas’s proprietary adhesive-based construction process. Queen Mary scientist Dr. Stoichko Dimitrov developed a new optical inspection technology to detect defects in sub-millimeter films, now applied in an industrial-scale system.
US Startups Driving Innovation
Despite political headwinds, US innovators are advancing perovskite technology. Startups like Swift Solar, Oxford PV, Solx (a Puerto Rican firm partnering with California’s Caelux Corporation), and Kentucky-based Sofab are making strides. Sofab, spun out of the University of Louisville’s Conn Center for Renewable Energy Research, develops nanoparticle inks that replace expensive materials used in perovskite cells. The startup uses a tin-based formula in partnership with Alpha Precision Systems and has collaborated with Australian firm Halocell to integrate its technology with roll-to-roll manufacturing. Sofab’s co-founders include Sashil Chapagain, Blake Martin, and Peter Armstrong. The Kentucky location gained early support through LaunchIt, UofL’s innovation bootcamp under the NSF I-Corps Site program. Sofab’s inks enable manufacturers to deposit critical layers using scalable, low-cost coating and printing techniques, reducing production costs while improving device performance and stability.