Approximate bandstructures of semiconductor alloys from tight-binding supercell calculations

By Timothy B. Boykin, N. Kharche, Gerhard Klimeck, M. Korkusiński. Journal of Physics: Condensed Matter, 2007

137 citations recorded by the source corpus.

Alloys such as AlGaAs, InGaAs, and SiGe find widespread usage in nanoelectronic devices such as quantum dots and nanowires. For these devices, in which the carriers probe nanometre-scale local disorder, the commonly employed virtual crystal approximation (VCA) is inadequate. Although the VCA produces small-cell E(k) relations it fails to include local disorder. In contrast, random-alloy supercell calculations do include local disorder but only deliver band extrema and supercell (not small cell) E(k) relations. Small-cell E(k) relations are, however, needed to interpret transport parameters such as effective masses. This work presents a method to extract the necessary approximate small-cell E(k) relations from the disordered supercell states. The method is applied to AlGaAs and gives significantly improved energy gaps versus the VCA, as well as approximate effective masses. The results illuminate the bowing of the Γ-valley gap and the good agreement with bulk experimental data shows that this method is well suited for nanodevices.

Subfields: Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/798673002a6dc11f1f3b2558d3d260e29c6995fc

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. Gerhard Klimeck
2. Blazej Grabowski
3. Fritz Körmann
4. Mark S. Lundstrom

In Electrical and Electronic Engineering

1. Blazej Grabowski
2. Yuji Ikeda
3. Timothy B. Boykin
4. Gerhard Klimeck
5. Fritz Körmann
6. Rajib Rahman

Citations in the corpus

• Atomistic Simulation of Realistically Sized Nanodevices Using NEMO 3-D—Part I: Models and Benchmarks (2007, background): “single-cell band structures from supercell band structure [35], [36], [37].”
• Ab initio phase stabilities and mechanical properties of multicomponent alloys: A comprehensive review for high entropy alloys and compositionally complex alloys (2019, methodology): “An approach which can overcome this issue is the band unfolding method [123,124] which has been recently employed to study binary solid solutions [125,126].”