Modeling and Simulation of Electrostatics of Ge$_{\text{1-x}}$Sn$_{\text{x}}$ Layers Grown on Ge Substrates

This work introduces a comprehensive simulation tool that provides a robust 1D Schrödinger – Poisson solver for modeling the electrostatics of heterostructures with an arbitrary number of layers, and non-uniform doping profiles along with the treatment of partial ionization of dopants at low temperatures. The effective masses are derived from the first-principles calculations. The solver is used to characterize three Ge_1-xSn_x/Ge heterostructures with non-uniform doping profiles and determine the subband structure at various temperatures. Here, the simulation results of the sheet carrier densities show excellent agreement with the experimentally extracted data, thus demonstrating the capabilities of the solver.. Authors: Gangwal, Siddhant [Arizona State University, Tempe, AZ (United States)] (ORCID:0009000709947750); Chen, Shunda [George Washington University, Washington, DC (United States)] (ORCID:0000000255067507); Li, Tianshu [George Washington University, Washington, DC (United States)] (ORCID:000000020529543X); Lu, Tzu-Ming [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)] (ORCID:0000000233631226); Vasileska, Dragica [Arizona State University, Tempe, AZ (United States)] (ORCID:0000000157492403). DOE Contract: AC02-05CH11231; NA0003525; SC0023412. Subjects: 42 ENGINEERING; Ge $_{\text{1-x}}$ Sn $_{\text{x}}$ /Ge heterostructures; Schrödinger – Poisson solver; Schrödinger – Poisson solver, partial ionization of dopants, low-temperature simulation, Ge1-xSnx/Ge heterostructures, density functional theory, quantum confinement.; density functional theory; low-temperature simulation; partial ionization of dopants; quantum confinement