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

• Published in: Journal of alloys and compounds 2021-12, Vol.885, p.161019, Article 161019
• Main Authors: Alhassan, Sultan, de Souza, Daniele, Alhassni, Amra, Almunyif, Amjad, Alotaibi, Saud, Almalki, Abdulaziz, Alhuwayz, Maryam, Kazakov, Igor P., Klekovkin, Alexey V., Tsekhosh, Vladimir I., Likhachev, Igor A., Pashaev, Elkhan.M., Souto, Sergio, Gobato, Yara Galvão, Saqri, Noor Al, Galeti, Helder Vinicius Avanço, Al mashary, Faisal, Albalawi, Hind, Alwadai, Norah, Henini, Mohamed
• Format: Article
• Language: English
• Subjects: Activation energy; Compressive properties; Current voltage characteristics; Deep level transient spectroscopy; Defects; Dilute bismides; Dilution; Doped semiconductor; Electrical properties; Electron traps; Epitaxial growth; Gallium arsenide; Hole traps; Molecular beam epitaxy; Optical activity; Optical properties; Orientation effects; Photoluminescence; Plane strain; Raman spectra; Schottky diodes; Spectrum analysis; Structural disorder; Substrates
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.161019

•I-V, C-V, DLTS, Laplace DLTS, Photoluminescence 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.•XRD results revealed that the in-plane strain in the GaAsBi layer of the samples grown on (100)-oriented substrate 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.•Samples grown on (311)B have better electrical and optical properties than samples grown on (100).•The photoluminescence and Raman spectra evidenced different compressive strain which affected considerably the optical properties. 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 affecte