Perovskite research turns to stability as Noak raises €5m for tandem scale-up

Noak's €5m seed points to tandem scale-up

The money comes from Belgium's Helios Foundation, Limburg-based climate investor Nuhma and V2HFin, a subsidiary of Flemish Energy Holding. It builds on the pair's tandem intellectual property. The partners say that intellectual property rests on more than a decade of research.

For buyers and manufacturers, tandems promise more power per panel and less use of expensive metals. Noak has not disclosed module prices, capacity or warranties.

The partners say the technology has logged five years of outdoor operation at more than ten test sites on three continents. The partners say the next phase will focus on demonstrating long-term stability and performance at scale. They call that key for bankability. The cell design adds a 3D woven back-contact foil. It moves electrical connections to the rear. That removes front-side metallisation and cuts shading losses. CEO Geert Palmers said the company aims to design a value chain through global industrial partnerships. He said it should not rely on vulnerable critical dominant dependencies.

Stability is the commercial gate

KIER's process uses nickel oxide powder. The powder attracts lithium ions out of the hole transport layer solution. The process then filters them away.

The champion cell reached 25.24% power conversion efficiency. It had an open-circuit voltage of 1.175 V, a short-circuit current density of 25.83 mA/cm2 and a fill factor of 83.21%. Stabilized output under one-sun illumination came in at 25.1%. The cells kept more than 90% of their initial efficiency after 500 hours of continuous operation. They kept 95% under accelerated damp-heat testing at 85 C and 85% relative humidity. Removing the lithium raised the hole transport layer's conductivity by a factor of 2.5.

Salts and zwitterions target defects

At Argonne National Laboratory, researchers used salt additives to control how perovskite crystals form. Two salts do the job: zinc bromide and methylammonium chloride. They lower the melting point of the perovskite material. Parts of the film then briefly liquefy, and atoms get time to settle into place.

The work appeared in Science. It produced 26.5% solar cell efficiency and 26.1% external quantum efficiency in an LED. "Defects have been the bottleneck for perovskites for almost a decade," said Yanqi Luo, a beamline scientist in Argonne's X-ray Science division. A Zhengzhou University review concluded that zwitterions can combine defect passivation, crystallization modulation and interfacial energy-level tuning in one molecule. The review cited L-asparagine lifting tin perovskite efficiency from 10.54% to 13.31%, and formamidine sulfinic acid reaching 22.06% in a wide-bandgap device. Tin cells lag far behind. A model-guided CsSnI3 device reached 10.76%, up from 8.98% for an unoptimized counterpart.