Optoelectronics advanced with graphene-like material

Posted Dec 22, 2017 by Tim Sandle
Scientists have observed the electronic structure of graphene in laboratory designed semiconductor. This finding could lead to advanced optoelectronics and data processing.
Making a superlattice with patterns of hydrogenated graphene is the first step in making the materia...
Making a superlattice with patterns of hydrogenated graphene is the first step in making the material suitable for organic chemistry. The process was developed in the Rice University lab of chemist James Tour.
Tour Lab/Rice University
The new development in materials science comes from Columbia University School of Engineering and Applied Science. Here technologists and scientists have successfully manipulated matter at the nanoscale. One study has led to a key breakthrough in materials science: the engineering of an "artificial graphene." This has come about by recreating the electronic structure of graphene in a semiconductor device.
The implications are important for improving the way computers process data. The findings could also make an important contribution to optoelectronics (the application of electronic devices and systems that source, detect and control light). An example is with photodiode, the semiconductor devices that converts light into an electrical current and which a central to solar cells.
The imnplications rest of an "artificial graphene". While graphene has many important properties, including very good conductivity, it is in the form of only one atomic arrangement, which can be constrictive. With an artificial graphene lattice, however, new spacings and configurations can be fashioned thereby making the material even more versatile.
To develop the new material the researchers used a method called nanolithography, deploying this to etch a new pattern into two-dimensional gallium arsenide. This process led to an alternate hexagonal lattice of sites where electrons are confined in a lateral direction, which is different to graphene. The new arrangement allows researchers to modulate electronic behavior.
Commenting on the research, principal scientist Professor Aron Pinczuk stated: "This milestone defines a new state-of-the-art in condensed matter science and nanofabrication."
The researcher goes on to explain the significance of the research: "Semiconductor artificial graphene devices could be platforms to explore new types of electronic switches, transistors with superior properties, and even, perhaps, new ways of storing information based on exotic quantum mechanical states."
The new research has been published in the journal Nature Nanotechnology under the title "Observation of Dirac bands in artificial graphene in small-period nanopatterned GaAs quantum wells."