Sublattice reversal in GaAs/Ge/GaAs (113)B heterostructures and its application to THz emitting devices based on a coupled multilayer cavity. (13th March 2018)

• Record Type: Journal Article
• Authors: Lu, Xiangmeng; Kumagai, Naoto; Minami, Yasuo; Kitada, Takahiro
• Is Part Of: Japanese journal of applied physics. Volume 57:Number 4(2018)Supplement
• Publication Date: 2018-03-13
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.57.04FH07
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We fabricated a coupled multilayer cavity with a GaAs/Ge/GaAs sublattice reversal structure for terahertz emission application. Sublattice reversal in GaAs/Ge/GaAs was confirmed by comparing the anisotropic etching profile of an epitaxial sample with those of reference (113)A and (113)B GaAs substrates. The interfaces of GaAs/Ge/GaAs were evaluated at the atomic level by scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDX) mapping. Defect-free GaAs/Ge/GaAs heterostructures were observed in STEM images and the sublattice lattice was directly seen through atomic arrangements in EDX mapping. A GaAs/AlAs coupled multilayer cavity with a sublattice reversal structure was grown on the (113)B GaAs substrate after the confirmation of sublattice reversal. Smooth GaAs/AlAs interfaces were formed over the entire region of the coupled multilayer cavity structure both below and above the Ge layer. Two cavity modes with a frequency difference of 2.9 THz were clearly observed.