Graphene is an atomic-scale hexagonal lattice pattern of pure carbon and scientists are thinking it could turn light into electricity. Graphene can turn one photon into many electrons, "showing much promise for future photovoltaic devices," according to Science X's Phys.org.
Graphene is cheap to produce - it can be peeled off of graphite or grown on top of other materials. The used of spectroscopic method shows that graphene can produce enough electrons to create an electrical current, according to a study published in Nano Letters.
In order to catch the super fast conversion of electrons, Jens Christian Johannsen from Marco Grioni's lab at EPFL, with colleagues at Aarhus University and ELETTRA in Italy, used a technique called "ultrafast time- and angle-resolved photoemission spectroscopy" (trARPES).
A tiny piece of graphene is put in an ultra-high vacuum chamber, according to Phys.org. A "pump" pulse of laser light then hits the graphene with "raises" the electrons in the graphene to higher energy states where they can conduct an electrical current.
"Doped" samples of graphene were used in the experiment. ("Doping" refers to the chemical addition or subtraction of electrons). During this trial, researchers discovered the "knock-on effect," according to Phys.org, or a sort of multiplication effect. When a photon excites an electron and then falls down to its regular state of energy, the fall excites two more electrons. "This indicates that a photovoltaic device using doped graphene could show significant efficiency in converting light to electricity," said Marco Grioni.
Scientists plan to experiment with molybdenum disulphide (MoS2), which has extraordinary "electronic and catalytic properties," according to Phys.org.
