Cornell researchers discover 3D semiconductor particles with 2D properties

According to the Ministry of Science and Technology's Cooperation Department, researchers at Cornell University have found that 3D semiconductor particles have 2D properties that can be used in photoelectrochemical processes - light is used to drive chemical reactions - to advance solar energy conversion technology. The research can also benefit renewable energy technologies that reduce carbon dioxide emissions, convert ammonia into hydrogen, and produce hydrogen peroxide. The research paper was published in the journal Nature Materials.

The researchers focused on the semiconductor bismuth vanadate, whose particles absorb light and then use the energy from it to oxidize water molecules. The semiconductor particles themselves come in a variety of shapes, with 3D surfaces that are angled with each other and intersect at the edges on the particle's curves. Not all planes are the same, and different structures produce different energy levels and electronic properties. The researchers found that three-dimensional particles can actually have the electronic properties of two-dimensional materials. In this case, the transition occurs gradually near the edge where the planes converge, the so-called transition zone. To "tune" the electronic properties and tailor the particles for photocatalytic processes, the properties can also be adjusted by chemically doping to change the width of the near-edge transition zone.