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Materials Science and Engineering Colloquium - "Tailoring semiconductor growth with light"

Event Type
Materials Science and Engineering Department
Dec 7, 2020   4:00 pm  
Kirstin Alberi, V-Materials Science, Materials Physics Group, The National Renewable Energy Laboratory, Golden Colorado
Originating Calendar
MatSE Colloquium Calendar

 "Tailoring semiconductor growth with light"


Synthesis of semiconductor compounds, alloys and heterostructures is often constrained by solubility limits, atomic diffusion and native defect formation, all of which can negatively impact their properties and performance. Modern uses of semiconductors therefore depend on our ability to control these processes during growth. Some degree of control is typically achieved by tuning two parameters: temperature and chemical potential.  Yet, there are many cases where additional degrees of freedom are desired.  In this talk, I will discuss the application of a third process variable: excess photogenerated carrier populations.  Non-equilibrium carrier concentrations are particularly useful, as they can be used to tune the quasi Fermi energies independently of extrinsic doping conditions, providing a way to further modify carrier exchange with defects, electric fields and desorption rates. I will detail our understanding of these mechanisms gained through experiments our group has carried out during molecular beam epitaxy of semiconductor alloys and heterostructures. I will also provide general guidance on ways in which to use light to overcome growth challenges based on these findings.

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