Engineers from Dartmouth Engineering in New Hampshire, in their recently published study, ‘Eliminating the Perovskite Solar Cell Manufacturing Bottleneck via High-Speed Flexography,’ claimed to have developed a rapid printing method to manufacture perovskite solar cells.

The engineers claim that the new method would make the sunlight-to-electricity conversion more efficient.

Even with their abundant absorber material, traditional metal halide perovskites face a scaling-up challenge due to slow production time, resulting in high manufacturing costs. The rapid printing process performed by engineers in the Dartmouth Engineering lab accelerates the total processing time of solar charge transport layers (CTLs) by 60 times without compromising reliability.

The new printing method pairs high-speed flexographic printing with rapidly annealed sol-gel inks, a method to produce solid materials from small molecules. The ink can be directly coated on the glass substrate in perovskites, coupled with antisolvent extraction.

Flexography is a form of rotary printing in which ink is applied to various surfaces using flexible rubber or other elastomeric printing plates.

The method involved scaling ultrathin nickel-oxide hole transport layers (HTLs) by pairing high-speed flexographic printing with rapidly annealed sol-gel inks to achieve the fastest reported process for fabrication of inorganic CTLs for perovskites. In this method, following the engineering precursor rheology for rapid film-leveling, nickel oxide HTLs were printed with high uniformity and ultralow pinhole densities resulting in photovoltaic performance exceeding that of spin-coated devices. Integrating these printed transport layers in planar inverted perovskite solar cells allows rapid fabrication of high efficiency with a power conversion efficiency greater than 15%.

Dartmouth Engineering Professor William Scheideler said, “Our method prints the solar cell layers with the speed and efficiency of a commercial newspaper printing press. This high manufacturing speed is important because it directly translates to lower cost per kWh, ultimately making solar energy more affordable for a larger population.”

Researchers worldwide have been performing various experiments to overcome the production scaling issues with perovskites, owing to their promising application for energy-efficient, thinfilm solar cells.

Recently, material scientists at the UCLA Samueli School of Engineering developed a new surface treatment during the manufacturing process of perovskites to overcome the degradation of cells due to prolonged exposure to sunlight.

Earlier this year, researchers at the Karlsruhe Institute of Technology (KIT) in Germany had developed colored solar cells from inexpensive perovskite semiconductor material, which can be integrated into facades or roofs of buildings and imitate the optics of building materials like marble.