Electrical spin injection into InGaAs/GaAs quantum wells: A comparison between MgO tunnel barriers grown by sputtering and molecular beam epitaxy methods - INSA Toulouse - Institut National des Sciences Appliquées de Toulouse Access content directly
Journal Articles Applied Physics Letters Year : 2014

Electrical spin injection into InGaAs/GaAs quantum wells: A comparison between MgO tunnel barriers grown by sputtering and molecular beam epitaxy methods

S. Liang
  • Function : Author
Xavier Devaux
Michel Hehn
S. Mangin
Thierry Amand
Yuan Lu

Abstract

An efficient electrical spin injection into an InGaAs/GaAs quantum well light emitting diode is demonstrated thanks to a CoFeB/MgO spin injector. The textured MgO tunnel barrier is fabricated by two different techniques: sputtering and molecular beam epitaxy. The maximal spin injection efficiency is comparable for both methods. Additionally, the effect of annealing is also investigated for the two types of samples. Both samples show the same trend: an increase of the electroluminescence circular polarization (Pc) with the increase of annealing temperature, followed by a saturation of Pc beyond 350 °C annealing. Since the increase of Pc starts well below the crystallization temperature of the full CoFeB bulk layer, this trend could be mainly due to an improvement of chemical structure at the top CoFeB/MgO interface. This study reveals that the control of CoFeB/MgO interface is essential for an optimal spin injection into semiconductor.

Dates and versions

hal-02050764 , version 1 (27-02-2019)

Identifiers

Cite

Philippe Barate, S. Liang, Tiantian Zhang, J. Frougier, M. Vidal, et al.. Electrical spin injection into InGaAs/GaAs quantum wells: A comparison between MgO tunnel barriers grown by sputtering and molecular beam epitaxy methods. Applied Physics Letters, 2014, 105 (1), pp.012404. ⟨10.1063/1.4887347⟩. ⟨hal-02050764⟩
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