Molecular Beam Epitaxy: An Essential Tool for Nanoscale Research and Applications

The unprecedented progress in nanoscale research in semiconductor and oxide materials has opened up many fascinating phenomena, which could have never been realized in a macroscopic scale. To give one of many examples, the bulk silicon (Si), which is an inefficient emitter of light due to its indirect band gap, could eventually emit strong intensity light when its physical structure is brought down to the nanometer scale. 
However, the mutation of the fundamental properties in such materials could only be realized when their structure and size could be manipulated in controlled way in the nanoscale regime. This has been practically possible only with the help of modern growth system such as molecular beam epitaxy technique.
In my presentation, I will show that by efficiently playing with the growth kinetics during molecular beam epitaxial process, one could, in principle be able to prepare semiconductor/oxide nanostructures of various dimensions. I will also show that how a new material system with multifunctional characteristics can be created by combining semiconductor (e.g. Si, Ge) nanostructures with crystalline oxide materials. Such nanostructures could be the ideal examples for studying various quantum phenomena for practical application. This is specially very important because the future challenge to nano scale electronic devices is relied on our ability to control and tailor both electronic and magnetic properties of materials to be used for preparing and processing the full electronic states in a single electronic device. 
In the last part of my talk, I will show that the knowledge we gained from semiconductor (e.g. Si) surface studies during epitaxial growth process, could be utilized to grow very different layer such as graphite like carbon (2 dimensional graphite) on silicon substrate. The growth of epitaxial graphene (2 dimensional graphite) on Si substrate has been one of the most challenging subjects since its discovery in 2004. If that is succeeded, it will bring a true revolution in the electronic and information technology because of the outstanding properties that Graphene has shown so far.