US researchers invent semiconductor crystal for better solar cells

25 June 2015 (Last Updated June 25th, 2015 18:30)

Researchers at Stanford University in California, US have invented a semiconductor crystal with variable band gap, which has enhanced electronic potential to capture more solar energy, making it more sensitive to a broader spectrum of light.

stanford university solar

Researchers at Stanford University in California, US have invented a semiconductor crystal with variable band gap, which has enhanced electronic potential to capture more solar energy, making it more sensitive to a broader spectrum of light.

The variable semiconductor material, Molybdenum disulfide or MoS2, is a rocky crystal, similar to quartz, which is refined to be used as a catalyst and a lubricant.

Stanford University mechanical engineer Xiaolin Zheng and physicist Hari Manoharan conducted the research to prove useful and unique electronic properties of MoS2, which is based on this crystal’s lattice formation.

Zheng said: "From a mechanical engineering standpoint, monolayer MoS2 is fascinating because its lattice can be greatly stretched without breaking."

"The process enabled MoS2 to turn into an artificial crystal with a variable band gap."

The university researchers stretched the lattice, which allowed the shift of atoms in its monolayer and resulted in change of the energy required to move electrons.

The process enabled MoS2 to turn into an artificial crystal with a variable band gap.

Manoharan said: "With a single, atomically thin semiconductor material, we can get a wide range of band gaps.

"We think this will have broad ramifications in sensing, solar power and other electronics."

Zheng added: "One of the most exciting things about our process is that is scalable. From an industrial standpoint, MoS2 is cheap to make."


Image: Stretched semiconductor material can capture better solar energy. Photo: courtesy of Stanford University.