Strain and spin dynamics approach in Ga(As)Sb quantum dot/well hybrid nanostructures

• Grant number: 21/10254-6
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Effective date (Start): January 10, 2022
• Effective date (End): May 09, 2022
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Marcio Daldin Teodoro
• Grantee: Gabriel Marques Jacobsen
• Supervisor: Gregory J. Salamo
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Research place: University of Arkansas, United States
• Associated to the scholarship: 18/06328-1 - Magneto-Raman instrumentation using a confocal microscope in cryogenic environments, BP.IC

Abstract

Recent efforts to improve antimony-based nanostructures growth techniques have allowed its incorporation on the traditional III-V semiconductor systems, opening an ample field for investigations on Condensed Matter Physics. Their relevance dwells on the optical emission dislocation towards telecom wavelengths (1.2 - 1.6 ¼m), strong spin-orbit coupling and possibility of type-II band alignment which makes them promise candidates for high efficiency optoelectronic devices, quantum information technology and single photon emitters. On that perspective, GaAsSb layer to cap quantum dots (QDs) have attracted great attention due to its unique properties such as suppressing the QD decomposition, once it acts as a strain reducing layer (SRL), and leading to a type-II band alignment for certain values of antimony (Sb) concentration. For instance, InAs/GaAsSb QDs have been widely investigated over the last few years and great steps for developing high efficiency QD solar cells have been accomplished. However, the weak luminescence emission as a result of carrier spatial separation and the hole dynamics modification are still remaining obstacles on this research area. An interesting and successful approach, yet few reports are found on the literature, is the growth of an interlayer between the quantum well and quantum dot, where the usual option is GaAs. This spacer is responsible for granting tuning of the hole confinement profile and also for strongly influencing on the optical properties and strain inside the structure. Therefore, this project is dedicated to study Ga(As)Sb quantum dot/well hybrid nanostructures with a GaAs interlayer and grown by molecular beam epitaxy (MBE) through photoluminescence (PL), excitation power and temperature dependent PL, time-resolved PL, photoluminescence excitation (PLE), X-ray diffraction and transmission electron and atomic force microscopy measurements. Also, Nextnano simulations will be carried on for providing better insights on the electronic and optical properties. The research will be developed at the Institute for Nanoscience and Engineering of the University of Arkansas, which possess all the equipment needed for the proposed analysis. (AU)