COMPUTATIONAL DESIGN OF STABLE, LIGHT EMITTING FUNCTIONALIZED GERMANIUM TIN SURFACES
Abstract
Semiconductor materials composed of Group IV elements have demonstrated promising properties for use in next-generation computing, communications, and photodetection technologies due to their ability to emit in the low- to mid-infrared wavelengths. The inclusion of Sn imparts desirable properties to electronic band structures in Ge and GeSi systems, including the possibility of direct transitions; however, the ability to synthesize structures of interest is limited by the low stability of Sn in Ge and GeSi. This project will obtain a deep understanding of fundamental aspects controlling the growth of GeSn and GeSiSn surfaces through the use of density functional theory calculations and kinetic Monte Carlo simulations. These rigorous calculations will elucidate the relative stability of varying materials structures along with the corresponding optoelectronic properties, identifying trends to guide the rational design of stable GeSn and GeSiSn structures. This project will identify surface modifications and compositions that maximize the favorable formation of Sn into GeSn and GeSiSn, yielding a detailed phase space as a function of surface thickness, surface geometry, and surface functionality. The effects of substrate composition and interatomic spacing on the stability and optoelectronic properties will be elucidated, seeking fundamental predictive insights into the formation of defects during the growth of GeSn and GeSiSn layers. Dynamic simulations will simulate the growth, annealing, and evolution of GeSn and GeSiSn surfaces; in combination with machine learning toolkits, this will enable a deep understanding of the roles of manipulable parameters on the uniform incorporation of Sn during growth. The fundamental insights enabled by this project will inform the synthesis of stable structures, enabling a computationally-driven predictive scheme for materials design and deployment.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 20, 2023
- Source ID
- FA95502210377
Entities
People
- Luke T Roling
Organizations
- Air Force Office of Scientific Research
- Iowa State University
- United States Air Force