Finite Element Analysis of Strain Effects on Electronic and Transport Properties in Quantum Dots and Wires

TL;DR

This paper develops a finite element method to analyze how nonuniform strain affects the electronic and transport properties of quantum dots and wires, linking mechanical strain to quantum electronic behavior.

Contribution

It introduces a finite element approach that incorporates strain effects into quantum electronic structure calculations for semiconductor nanostructures.

Findings

Strain significantly alters the density of states in quantum structures.

The model's results align with experimental I(V) measurements.

The method enables detailed analysis of strain-induced electronic property changes.

Abstract

Lattice mismatch in layered semiconductor structures with submicron length scales leads to extremely high nonuniform strains. This paper presents a finite element technique for incorporating the effects of the nonuniform strain into an analysis of the electronic properties of SiGe quantum structures. Strain fields are calculated using a standard structural mechanics finite element package and the effects are included as a nonuniform potential directly in the time independent Schrodinger equation; a k-p Hamiltonian is used to model the effects of multiple valence subband coupling. A variational statement of the equation is formulated and solved using the finite element method. This technique is applied to resonant tunneling diode quantum dots and wires; the resulting densities of states confined to the quantum well layers of the devices are compared to experimental current-voltage I(V) curves.