Nanoscale assembly of silicon-like [Al(As1-xNx)] ySi5-2y alloys: Fundamental theoretical and experimental studies of structural and optical properties

L. Jiang, P. E. Sims, G. Grzybowski, R. T. Beeler, Andrew Chizmeshya, David Smith, John Kouvetakis, Jose Menendez

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Ab initio theoretical simulations of Al(As1-xN x)Si3 alloys, a new class of optoelectronic materials, confirm that these compounds are likely to be disordered via a mechanism that preserves the integrity of the constituent III-V-Si3 tetrahedra but randomizes their orientation in the average diamond lattice of the compound. This type of disorder is consistent with experimental structural data and with the proposed growth mechanism for such alloys, according to which "III:V(SiH3)3" intermediate complexes are formed in the gas phase from reactions between group-III atomic beams and V(SiH 3)3 molecules, delivering the entire III-V-Si3 tetrahedra to the growing film. Experimental optical studies of these Al(As1-xNx)Si3 alloys as well as more general [Al(As1-xNx)]ySi5-2y compounds grown on Si substrates were carried out using spectroscopic ellipsometry. The resulting dielectric functions are found to be similar to broadened versions of their counterparts in pure Si. This broadening may have important practical applications, particularly in photovoltaics, because it dramatically enhances the optical absorption of Si in the visible range of the electromagnetic spectrum. A critical point analysis reveals the existence of direct optical transitions at energies as low as 2.5 eV, well below the lowest direct absorption edge of Si at 3.3 eV. Such transitions are predicted theoretically for perfectly ordered III-V-Si3 compounds, and the experimental results suggest that they are robust against tetrahedra orientational disorder.

Original languageEnglish (US)
Article number045208
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume88
Issue number4
DOIs
StatePublished - Jul 31 2013

Fingerprint

Silicon
tetrahedrons
Structural properties
Optical properties
assembly
optical properties
silicon
disorders
Atomic beams
electromagnetic spectra
Diamond
Optical transitions
Spectroscopic ellipsometry
atomic beams
Film growth
optical transition
Optoelectronic devices
integrity
Light absorption
ellipsometry

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

@article{4d46254f418a4517947df7cd7e733391,
title = "Nanoscale assembly of silicon-like [Al(As1-xNx)] ySi5-2y alloys: Fundamental theoretical and experimental studies of structural and optical properties",
abstract = "Ab initio theoretical simulations of Al(As1-xN x)Si3 alloys, a new class of optoelectronic materials, confirm that these compounds are likely to be disordered via a mechanism that preserves the integrity of the constituent III-V-Si3 tetrahedra but randomizes their orientation in the average diamond lattice of the compound. This type of disorder is consistent with experimental structural data and with the proposed growth mechanism for such alloys, according to which {"}III:V(SiH3)3{"} intermediate complexes are formed in the gas phase from reactions between group-III atomic beams and V(SiH 3)3 molecules, delivering the entire III-V-Si3 tetrahedra to the growing film. Experimental optical studies of these Al(As1-xNx)Si3 alloys as well as more general [Al(As1-xNx)]ySi5-2y compounds grown on Si substrates were carried out using spectroscopic ellipsometry. The resulting dielectric functions are found to be similar to broadened versions of their counterparts in pure Si. This broadening may have important practical applications, particularly in photovoltaics, because it dramatically enhances the optical absorption of Si in the visible range of the electromagnetic spectrum. A critical point analysis reveals the existence of direct optical transitions at energies as low as 2.5 eV, well below the lowest direct absorption edge of Si at 3.3 eV. Such transitions are predicted theoretically for perfectly ordered III-V-Si3 compounds, and the experimental results suggest that they are robust against tetrahedra orientational disorder.",
author = "L. Jiang and Sims, {P. E.} and G. Grzybowski and Beeler, {R. T.} and Andrew Chizmeshya and David Smith and John Kouvetakis and Jose Menendez",
year = "2013",
month = "7",
day = "31",
doi = "10.1103/PhysRevB.88.045208",
language = "English (US)",
volume = "88",
journal = "Physical Review B-Condensed Matter",
issn = "0163-1829",
publisher = "American Institute of Physics Publising LLC",
number = "4",

}

TY - JOUR

T1 - Nanoscale assembly of silicon-like [Al(As1-xNx)] ySi5-2y alloys

T2 - Fundamental theoretical and experimental studies of structural and optical properties

AU - Jiang, L.

AU - Sims, P. E.

AU - Grzybowski, G.

AU - Beeler, R. T.

AU - Chizmeshya, Andrew

AU - Smith, David

AU - Kouvetakis, John

AU - Menendez, Jose

PY - 2013/7/31

Y1 - 2013/7/31

N2 - Ab initio theoretical simulations of Al(As1-xN x)Si3 alloys, a new class of optoelectronic materials, confirm that these compounds are likely to be disordered via a mechanism that preserves the integrity of the constituent III-V-Si3 tetrahedra but randomizes their orientation in the average diamond lattice of the compound. This type of disorder is consistent with experimental structural data and with the proposed growth mechanism for such alloys, according to which "III:V(SiH3)3" intermediate complexes are formed in the gas phase from reactions between group-III atomic beams and V(SiH 3)3 molecules, delivering the entire III-V-Si3 tetrahedra to the growing film. Experimental optical studies of these Al(As1-xNx)Si3 alloys as well as more general [Al(As1-xNx)]ySi5-2y compounds grown on Si substrates were carried out using spectroscopic ellipsometry. The resulting dielectric functions are found to be similar to broadened versions of their counterparts in pure Si. This broadening may have important practical applications, particularly in photovoltaics, because it dramatically enhances the optical absorption of Si in the visible range of the electromagnetic spectrum. A critical point analysis reveals the existence of direct optical transitions at energies as low as 2.5 eV, well below the lowest direct absorption edge of Si at 3.3 eV. Such transitions are predicted theoretically for perfectly ordered III-V-Si3 compounds, and the experimental results suggest that they are robust against tetrahedra orientational disorder.

AB - Ab initio theoretical simulations of Al(As1-xN x)Si3 alloys, a new class of optoelectronic materials, confirm that these compounds are likely to be disordered via a mechanism that preserves the integrity of the constituent III-V-Si3 tetrahedra but randomizes their orientation in the average diamond lattice of the compound. This type of disorder is consistent with experimental structural data and with the proposed growth mechanism for such alloys, according to which "III:V(SiH3)3" intermediate complexes are formed in the gas phase from reactions between group-III atomic beams and V(SiH 3)3 molecules, delivering the entire III-V-Si3 tetrahedra to the growing film. Experimental optical studies of these Al(As1-xNx)Si3 alloys as well as more general [Al(As1-xNx)]ySi5-2y compounds grown on Si substrates were carried out using spectroscopic ellipsometry. The resulting dielectric functions are found to be similar to broadened versions of their counterparts in pure Si. This broadening may have important practical applications, particularly in photovoltaics, because it dramatically enhances the optical absorption of Si in the visible range of the electromagnetic spectrum. A critical point analysis reveals the existence of direct optical transitions at energies as low as 2.5 eV, well below the lowest direct absorption edge of Si at 3.3 eV. Such transitions are predicted theoretically for perfectly ordered III-V-Si3 compounds, and the experimental results suggest that they are robust against tetrahedra orientational disorder.

UR - http://www.scopus.com/inward/record.url?scp=84883093582&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84883093582&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.88.045208

DO - 10.1103/PhysRevB.88.045208

M3 - Article

AN - SCOPUS:84883093582

VL - 88

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 0163-1829

IS - 4

M1 - 045208

ER -