Growth temperature optimization of interfacial misfit technique for growth of GaSb subcells on GaAs substrates

A. Mansoori, S. J. Addamane, E. J. Renteria, D. M. Shima, V. S. Mangu, Ehsan Vadiee, Christiana Honsberg, G. Balakrishnan

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Access to lattice matched narrow bandgap semiconductors is a challenge for improved efficiency of GaAs based multi-junction solar cells (MJSCs). GaSb has a bandgap of 0.72 eV and is ideally suited to be used as a Near-Infrared subcell for MJSCs. However, when used as a replacement for Germanium in GaAs based MJSCs, the large lattice mismatch between GaSb and GaAs results in significant threading dislocation density in the GaSb subcell. The threading dislocation density in the GaSb epilayer can be reduced to a certain extent by the realization of 90° interfacial misfit dislocation arrays (IMF) between the GaSb and GaAs layers. The substrate temperature during the growth of the GaSb epi-layer on GaAs has a strong impact on the threading dislocation density while making use of the IMF technique. In this study, several substrate temperatures (ranging from 350°C to 540°C) are explored to achieve reduced threading dislocation density which is measured using both plan-view Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD) rocking curve analysis. A low growth temperature (of 420°C) shows the reduction of threading dislocation to the level of ∼1.3×108 cm-2.

Original languageEnglish (US)
Title of host publication2018 IEEE 7th World Conference on Photovoltaic Energy Conversion, WCPEC 2018 - A Joint Conference of 45th IEEE PVSC, 28th PVSEC and 34th EU PVSEC
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages917-920
Number of pages4
ISBN (Electronic)9781538685297
DOIs
Publication statusPublished - Nov 26 2018
Event7th IEEE World Conference on Photovoltaic Energy Conversion, WCPEC 2018 - Waikoloa Village, United States
Duration: Jun 10 2018Jun 15 2018

Other

Other7th IEEE World Conference on Photovoltaic Energy Conversion, WCPEC 2018
CountryUnited States
CityWaikoloa Village
Period6/10/186/15/18

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Keywords

  • GaSb
  • growth temperature optimization
  • IMF
  • interfacial misfit array
  • thermophotovoltaic

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Renewable Energy, Sustainability and the Environment
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

Cite this

Mansoori, A., Addamane, S. J., Renteria, E. J., Shima, D. M., Mangu, V. S., Vadiee, E., ... Balakrishnan, G. (2018). Growth temperature optimization of interfacial misfit technique for growth of GaSb subcells on GaAs substrates. In 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion, WCPEC 2018 - A Joint Conference of 45th IEEE PVSC, 28th PVSEC and 34th EU PVSEC (pp. 917-920). [8547684] Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/PVSC.2018.8547684