PHOTO : Materials - Epitaxy of novel III-V-Bi semiconductor alloys
The addition of bismuth, element V, in a GaAs matrix shifts very effectively its emission wavelength towards the infrared range. Thus, 1 eV is achieved by adding 6% Bi in thin layers and 7% Bi in quantum wells. The applications of Bi alloying are very diverse, and we mainly target photovoltaics, spintronics and laser emission.
We study the impact of the different growth parameters, to which the incorporation of this atomic element is very sensitive, since Bi is significantly different from the constituent elements of GaAs. Our approach consists in taking advantage of the wide range of techniques for real-time monitoring of its epitaxy at our disposal, one of which, recently developed at LAAS, opens up the fine measurement of the curvature of constrained structures such as GaAsBi/GaAs. Access to these measurements made it possible to demonnstrate the impact of the surface reconstruction during the incorporation of Bi.
Left: Room temperature photoluminescence of GaAsBi 150nm thick layers with various Bi contents (coll. LPCNO). Right: Real time measurements of the curvature resulting from Bi incorporation. It shows the impact of surface reconstruction upon Bi incorporation.
LPCNO, INSA, Toulouse – CEMES, CNRS, Toulouse – LPCMI – Univ. P. Sabatier, Toulouse – University of Istanbul, Turkey - Univ. Varsovie, Poland – IMT- Bucarest, Romania – Tyndall, Cork, Ireland
Related publications :
S. Azaizia, A. Balocchi, S. Mazzucato, F. Cadiz, F. Beato de le Salle, H. Lehec, A. Arnoult, D. Lagarde, T. Amand, C. Fontaine, H. Carrere, X. Marie, "Bismuth Content Dependence of the Electron Spin Relaxation Time in GaAsBi Epilayers and Quantum Well Structures," Semiconductor Science and Technology 33, 114013, 2018. F. Dybała, J. Kopaczek, M. Gladysiewicz, E.-M. Pavelescu, C. Romanitan, O. Ligor, A. Arnoult, C. Fontaine and R. Kudrawiec, "Electromodulation spectroscopy of heavy-hole, light-hole, and spin-orbit transitions in GaAsBi layers at hydrostatic pressure," Applied Physics Letters 111(19), 192104, 2017. H. Makhloufi, P.Boonpeng, S. Mazzucato, J. Nicolai, A.Arnoult, T. Hungria, G. Lacoste, C. Gatel, A. Ponchet, H. Carrere, X. Marie, C. Fontaine, "Molecular beam epitaxy and properties of GaAsBi/GaAs quantum wells grown by molecular beam epitaxy – Effect of thermal annealing," Nanosc. Res. Lett. 9, 123, 2014. B. A. Broderick, S. Mazzucato, H. Carrere, T. Amand, H. Makhloufi, A. Arnoult, C. Fontaine, O. Donmez, A. Erol, M. Usman, E.P. O’Reilly, X. Marie, "Anisotropic electron g-factor as a probe of the electronic structure of GaBixAs1-x / GaAs epilayers," Phys. Rev. B 90, 195301, 2014.