New materials make cheap and efficient solar cells

In two new studies, scientists have announced new ways to make cheaper, more efficient photovoltaics.

In a project, researchers at the University of Toronto have shown that nickel can replace gold in electrical contacts of colloidal quantum solar cells.

In another project, a team at Lawrence Berkeley National Laboratory in California added selenium to zinc oxide, and significantly increased its efficiency in absorbing sunlight.

Both studies can provide a more realistic cost-effective photovoltaic technology.

Quantum solar cells are already cheap because the particles themselves (also known as nanocrystal) are nano-sized semiconductor materials produced through low-cost chemical reactions.

Electricity generated from these quanta is usually recovered through electrical contacts made of gold, but researchers in the University of Toronto Electrical Engineering Research Program have succeeded in using the Nickel-free, but still unchanged.

Initially, when tested with nickel, it was mixed with quantum particles, forming a compound that prevents electrical current.

However, by adding only one nanometer of lithium fluoride to the middle of the nickel and quantum particles created a 'barrier' that prevented the two entities from mixing together and allowed the current to flow from the quantum particles. to nickel.

Researchers say using nickel-based contactors, the cost of solar cell material will decrease by 40-80%, and they are expected to commercialize the technology once it can be increased. general performance of solar cells.

Like nanocrystal, zinc oxide is also a low cost material. However, the challenge of this approach is to increase the absorption capacity of solar energy.

The Berkeley Research Team succeeded by adding selenium. And just adding 9% of selenium to zinc oxide, they have seen a remarkable effect on the ability to absorb sunlight.