Ab initio calculation of the CdSe/CdTe heterojunction band offset using the local-density approximation-1/2 technique with spin-orbit corrections

Author(s)

Ribeiro, Jr., M. ^{[1, 2]} ; Fonseca, L. R. C. ^[3] ; Sadowski, T. ^[4] ; Ramprasad, R. ^[4]

Affiliation

^[1] Univ Sao Paulo, Inst Fis, Dept Fis Mat & Mecan, BR-05315970 Sao Paulo - Brazil

^[2] Ctr Pesquisas Avancadas Wernher von Braun, BR-13098392 Campinas, SP - Brazil

^[3] Univ Estadual Campinas, Ctr Semicond Components, BR-13083870 Campinas, SP - Brazil

^[4] Univ Connecticut, Inst Mat Sci, Dept Chem Mat & Biomol Engn, Storrs, CT 06269 - USA

• Document type: Journal article
• Source: Journal of Applied Physics; v. 111, n. 7 APR 1 2012.
• Web of Science Citations: 14

Abstract

We performed ab initio calculations of the electronic structures of bulk CdSe and CdTe and of their interface. We employed the local-density approximation-1/2 self-energy correction scheme {[}L. G. Ferreira, M. Marques, and L. K. Teles, Phys. Rev. B 78, 125116 (2008)] to obtain improved band gaps and band offsets, as well as spin-orbit coupling to further correct the valence band edges. Our results are in good agreement with experimental values for bulk band gaps and reproduce the staggered band alignment characteristic of this system. We found that the spin-orbit effect is of considerable importance for the bulk band gaps, but has little impact on the band offset of this particular system. Moreover, the electronic structure calculated along the 61.4 angstrom transition region across the CdSe/CdTe interface shows a non-monotonic variation of the bandgap in the range 0.8-1.8 eV. This finding may have important implications to the absorption of light along the interface between these two materials in photovoltaic applications. (C) 2012 American Institute of Physics. {[}http://dx.doi.org/10.1063/1.3699054] (AU)

• FAPESP's process: 06/05858-0 - Theoretical study of semiconductor alloys for applications in spintronics and optoelectronics
• Grantee: Lara Kühl Teles
• Support Opportunities: Research Grants - Young Investigators Grants