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

In this paper, a numerical simulation method was used, based on the solution of the basic semiconductor equations. This gives an access to microscopic and macroscopic properties of the structure, and thereon, to an understanding of the electrical properties of Ge_1-xSn_x/Ge by linking quantities such as admittance spectra to microscopic variations in the structure. A 200 nm thick p-doped Ge_1-xSn_x layer (x≈0.05) on top of a 100 μm por n-Ge substrate was modeled, including a Shockley Read Hall trap with energy near the valence band.