Unification of the phonon mode behaviour in semiconductor alloys: Theory and ab initio calculations

Abstract

We demonstrate how to overcome serious problems in understanding and classification of vibration spectra in semiconductor alloys, following from traditional use of the virtual crystal approximation (VCA). We show that such different systems as InGaAs (1-bond->1-mode behavior), InGaP (modified 2-mode) and ZnTeSe (2-bond->1-mode) obey in fact the same phonon mode behavior - hence probably a universal one - of a percolation-type (1-bond->2-mode). The change of paradigm from the `VCA insight' (an averaged microscopic one) to the `percolation insight' (a mesoscopic one) offers a promising link towards the understanding of alloy disorder. The discussion is supported by ab initio simulation of the phonon density of states at the zone-center of representative supercells at intermediary composition (ZnTeSe) and at the impurity-dilute limits (all systems). In particular, we propose a simple ab initio `protocol' to estimate the basic input parameters of our semi-empirical `percolation' model for the calculation of the 1-bond->2-mode vibration spectra of zincblende alloys. With this, the model turns self-sufficient.

updated and extended form, to be published in Phys.Rev.B

References in corpus (2)

• (Ga,In)P: A standard alloy in the classification of phonon mode behavior
• Linearized force constants method for lattice dynamics in mixed semiconductors

Cited by in corpus (4)

• Phonon confinement and substitutional disorder in Cd1-xZnxS Nanocrystals
• Structural properties and Raman spectra of columbite-type NiNb${}_{2-x}$V${}_x$O${}_6$ synthesized under high pressure
• Phonon-based partition of (ZnSe-like) semiconductor mixed crystals on approach to their pressure-induced structural transition
• Secondary phase Cu2SnSe3 vs. kesterite Cu2ZnSnSe4: similarities and differences in lattice vibration modes