Optical study of narrow band gap InAsxSb1x (x=0, 0.25, 0.5, 0.75, 1) alloys

Shirin Namjoo, Amir S. H. Rozatian, Iraj Jabbari, and Peter Puschnig
Phys. Rev. B 91, 205205 – Published 13 May 2015

Abstract

The structural, electronic, and optical properties of InAs, InSb, and their ternary alloys InAsxSb1x (x=0.25, 0.5, 0.75) are investigated within density functional theory utilizing the wien2k package. We find that the lattice constants and bulk moduli as a function of x are in best agreement with Vegard's linear rule. When computing the electronic band structures with the modified Becke-Johnson exchange-correlation functional (mBJLDA), our results for the band gaps of InAs, InSb, and their ternary alloys are in good agreement with the available experimental results while the conventional Wu-Cohen generalized gradient approximation (GGA) functional leads to zero or close to zero band gaps. In particular, our mBJLDA results confirm experimental evidence that the minimum band gap occurs for As concentrations around x0.3. Furthermore, we investigate the dielectric function of these compounds within the random phase approximation using both the Wu-Cohen GGA and the mBJLDA functionals. While the mBJLDA results of our fully first-principles calculations show good agreement of the peak positions in ε2(ω) with experiments, the peaks in the optical spectra based on the Wu-Cohen GGA band structure appear redshifted compared to experiment. We further identify the interband transitions responsible for the structures in the spectra. Looking at the optical matrix element, we note that the major peaks are dominated by transition from the Sb 5p (As 4p) states to In s states for InSb and InAs0.25Sb0.75 (InAs, InAs0.75Sb0.25, and InAs0.5Sb0.5).

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 4 March 2015
  • Revised 28 April 2015

DOI:https://doi.org/10.1103/PhysRevB.91.205205

©2015 American Physical Society

Authors & Affiliations

Shirin Namjoo*

  • Department of Physics, University of Isfahan, Hezar Jarib Street, Isfahan 81746-73441, Iran and University of Graz, Institute of Physics, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria

Amir S. H. Rozatian

  • Department of Physics, University of Isfahan, Hezar Jarib Street, Isfahan 81746-73441, Iran

Iraj Jabbari

  • Faculty of New Sciences and Technology, University of Isfahan, Hezar Jarib Street, Isfahan 81746-73441, Iran

Peter Puschnig

  • University of Graz, Institute of Physics, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria

  • *namjoo_sh@yahoo.com
  • a.s.h.rozatian@phys.ui.ac.ir

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 91, Iss. 20 — 15 May 2015

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×