Electrical Characterization of P-Ge1-xSnx/P-Ge and P-Ge1-xSnx/n-Ge Heterostructures by Numerical Simulation of Admittance Spectroscopy

摘要

The group IV semiconductor alloy germanium tin (Ge1-xSnx) is an attractive material for next-generation devices in nanoelectronics. The strain resulting from the lattice mismatch between an epitaxial film and the substrate material provides an efficient tool for band structure engineering and device performance boosting. However, Ge1-xSnx alloys started to receive attention only recently, with advances in epitaxial growth techniques allowing Ge1-xSnx epilayers to be grown with high crystalline quality. Therefore, although recognized as a potential candidate for many applications[3][4], the detailed electronic properties of Ge1-xSnx compounds are not yet clearly understood. This was our motivation to carry out a theoretical study of Ge1-xSnx/Ge heterostructures. Admittance spectroscopy is a popular analytical tool in materials research and development because it involves a relatively simple electrical measurement whose results may establish accurate characteristics of materials.