Sol Voltaics AB of Lund, Sweden, which is developing nanomaterials technology for enhancing solar cell efficiency, says that it has taken a significant step towards commercializing its efficiency-boosting solar technology by completing the manufacture of photovoltaic (PV) nanowires using its proprietary Aerotaxy process. This paves the way for the firm to bring its SolFilm PV solutions to market, delivering solar module power boosts of up to 50% at very low cost, it is claimed.
“Producing solar nanowires through Aerotaxy is the key to manufacturing our SolFilm,” says CEO Erik Smith. The nanowires are grown such that the top and bottom of the wire have opposite doping profiles. This makes each nanowire a fully functional solar cell, with a pn junction along the length of the wire. “Whether used by module manufacturers as a single-junction, high-efficiency, low-cost solution or as a boosting technology [in a tandem cell atop another material], we believe SolFilm will usher in a new age of solar power efficiencies,” he adds.
Increasing solar efficiencies at economies of scale has dramatically slowed in recent years, with conventional modules seeing an average annual efficiency increase of just 0.2-0.3%, notes Sol Voltaics. With many emerging efficiency-boosting technologies continuing to be prohibitively expensive, unstable or lacking reliability, SolFilm offers solar panel makers an economically viable bridge with a proven material to generate previously unreachable solar efficiencies, the firm reckons.
SolFilm is a lightweight photonic film consisting of billions of gallium arsenide (GaAs) nanowires oriented facing the sun. Each nanowire is a complete solar cell, converting high-energy sunlight directly into power. Previously used mostly in space and concentrated photovoltaic (CPV) solar projects, GaAs has long held great potential for the mainstream solar industry but its high fabrication costs have prevented economical fabrication of large solar panels, says Sol Voltaics. Manufacturing nanowires with Aerotaxy dramatically reduces the required amount of GaAs and removes the need for a crystalline support wafer, significantly lowering material costs, claims the firm. Sol Voltaics reckons that, with the recent results, it has taken a step towards delivering an increase in power for conventional solar modules while reducing the price of solar energy.
Sol Voltaics, which last year became the first company to successfully align nanowires in a thin film, was recently recognised as ‘Company of the Year’ at the Rapidus Awards, which recognises excellence in innovation as well as companies that have the greatest potential for future success. Last May, the firm also completed a $17m investment in new equity, including $4.5m in funding from the Swedish Energy Agency and the European Union’s Horizon 2020 research and innovation program.