Investigation of the effect of substrate orientation on the structural, electrical and optical properties of n-type GaAs1−xBix layers grown by Molecular Beam Epitaxy

Sultan Alhassan, Daniele de Souza, Amra Alhassni, Amjad Almunyif, Saud Alotaibi, A. Almalki, M. Alhuwayz, Igor P. Kazakov, Alexey V. Klekovkin, Vladimir I. Tsekhosh, Igor A. Likhachev, Elkhan M. Pashaev, Sergio Souto, Yara Galvão Gobato, N. Al Saqri, Helder Vinicius Avanço Galeti, Faisal Al mashary, Hind Albalawi, Norah Alwadai, Mohamed Henini*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Current-Voltage (I-V), Capacitance-Voltage (C-V), Deep Level Transient Spectroscopy (DLTS), Laplace DLTS, Photoluminescence (PL) and Micro-Raman techniques have been employed to investigate the effect of the orientation of the substrates on the structural, electrically and optically active defects in dilute GaAs1−xBix epilayers structures having a Bi composition x = ~5.4%, grown by Molecular Beam Epitaxy (MBE) on (100) and (311)B GaAs planes. X-ray diffraction results revealed that the in-plane strain in the Ga(As,Bi) layer of the samples grown on (100)-oriented substrate (−0.0484) is significantly larger than that of the samples grown on (311)B-oriented substrate. The substrate orientation is found to have a noticeable impact on the Bi incorporation and the electrical properties of dilute GaAsBi Schottky diodes. The I-V characteristics showed that (100) Schottky diodes exhibited a larger ideality factor and higher barrier height compared with (311)B samples. The DLTS measurements showed that the number of electrically active traps were different for the two GaAs substrate orientations. In particular, three and two electron traps are detected in samples grown on (100) and (311)B GaAs substrates, respectively, with activation energies ranging from 0.12 to 0.41 eV. Additionally, one hole trap was observed only in sample grown on (100) substrates with activation energy 0.24 eV. The observed traps with small activation energies are attributed to Bi pair defects. The photoluminescence (PL) and Raman spectra have evidenced different compressive strain which affects considerably the optical properties. Furthermore, the PL spectra were also affected by different contributions of Bi- related traps which are different for different substrate orientation in agreement with DLTS results.

Original languageEnglish
Article number161019
JournalJournal of Alloys and Compounds
Volume885
DOIs
Publication statusPublished - Dec 10 2021
Externally publishedYes

Keywords

  • Defects
  • Dilute bismides
  • Doped semiconductor
  • Electrical properties
  • Optical properties
  • Structural disorder

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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