Researchers claim low-cost solar cells based on abundant metals

PARIS – Researchers at the University of Basel, in Switzerland, said they have defined an approach to developing sustainable and renewable photovoltaics devices. This approach paves the way for low-cost solar cells based on abundant metals, according to an article published in the Chemical Communications journal.

Dye-sensitized solar cells (DSCs) consist of a semiconductor, titanium dioxide, which is coated with a colored dye. The dye absorbs sunlight and injects an electron into the semiconductor. This is the primary event leading to the photocurrent, chemists said.

Researchers claimed they have achieved two breakthroughs. Firstly, they said they have developed a strategy for making and attaching colored materials to the surface of titanium dioxide nanoparticles. Secondly, they said that they have demonstrated that simple compounds of the readily available metal zinc may be used. The achievement was finding a method for the simultaneous synthesis of the dye and its attachment to the semiconductor surface, the team said.

Dye-sensitized solar cells have been assembled using a sequential approach: a TiO2 surface was functionalized with an anchoring ligand, followed by metallation with Zn(OAc)2 or ZnCl2, and subsequent capping with a chromophore functionalized 2,2':6',2''-terpyridine; the DSCs exhibit surprisingly good efficiencies confirming the effectiveness of the new strategy for zinc-based DSC fabrication.


The team of chemists noted that DSCs use ruthenium dyes, but ruthenium is very rare and expensive. Then, they have demonstrated that dyes from abundant and relatively inexpensive copper were effective in DSCs and the extension to cheap zinc compounds further increases the sustainability of the materials science.

"This is a significant step towards our dream of coupling photovoltaics and lighting in an intelligent curtain which can store solar energy during the day and function as a lighting device at night,” declared Ed Constable, professor at the University of Basel, in a statement. “This is at the core of our ERC research program Light-In, Light-Out."