A5055136462- Semiconductor Quantum Structures and Devices
- Advanced Materials Characterization Techniques
- Advanced Semiconductor Detectors and Materials
- Electronic and Structural Properties of Oxides
- GaN-based semiconductor devices and materials
- Semiconductor materials and interfaces
- Surface and Thin Film Phenomena
- Advanced Thermoelectric Materials and Devices
- Ga2O3 and related materials
- Quantum Dots Synthesis And Properties
- Phase-change materials and chalcogenides
- Metal and Thin Film Mechanics
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor materials and devices
- Ion-surface interactions and analysis
- Quantum and electron transport phenomena
- Integrated Circuits and Semiconductor Failure Analysis
- Topological Materials and Phenomena
University of Michigan
2019-2025
Semiconductor quantum dots (QDs) are nanostructures that can enhance the performance of electronic devices due to their 3D quantization. Typically, heterovalent impurities, or dopants, added semiconducting QDs provide extra electrons and improve conductivity. Since each QD is expected contain a few parent dopants have been difficult locate. In this work, we investigate spatial distribution donors in epitaxial InAs/GaAs using local-electrode atom-probe tomography self-consistent...
We have investigated the influence of non-stoichiometry and local atomic environments on carrier transport in GaAs(N)Bi alloy films using local-electrode atom probe tomography (LEAP) conjunction with time-resolved terahertz photoconductivity measurements. The concentrations N, Bi, excess As, as well Bi pair correlations, are quantified LEAP. Using THz measurements, we show that is primarily limited by highest mobilities for layers yBi > 0.035.
We examine the influence of quantum dot (QD) morphology on optical properties two-dimensional (2D) GaSb/GaAs multilayers, with and without three-dimensional nanostructures. Using nanostructure sizes from scanning transmission electron microscopy local Sb compositions local-electrode atom-probe tomography as input into self-consistent Schrödinger–Poisson simulations based 8 × k·p theory, we compute confinement energies for QDs, circular arrangements smaller termed QD-rings, 2D layers GaAs...
We examine the formation and properties of InGaN quantum dots (QDs) on free-standing GaN GaN/sapphire templates, with without buried InGaN/GaN QD superlattices (SLs). use scanning tunneling microscopy (STM) spectroscopy to image QDs measure their electronic states. As number layers preceding increases (i.e., increasing substrate complexity), total density increases. For GaN, STM reveals a mono-modal QD-size-distribution, consistent limited threading dislocations serving as heterogeneous...
We investigate the influence of strain and dislocations on band alignment in GaSb/GaAs quantum dot systems. Composition profiles from cross-sectional scanning tunneling microscopy images are interpolated onto a finite element mesh order to calculate distribution local elastic strain, which is converted spatially varying using deformation potential theory. Our calculations predict that dislocation-induced relaxation charging lead significant variations alignment. Furthermore, misfit induces...
We probe the conduction-band offsets (CBOs) and confined states at GaAs/GaAsNBi quantum wells (QWs). Using a combination of capacitance–voltage (C–V) measurements self-consistent Schrödinger–Poisson simulations based on effective mass approximation, we identify an N-fraction dependent increase in CBO, consistent with trends predicted by band anti-crossing model. computed electron conjunction photoluminescence spectroscopy data, show that N mainly influences conduction states, relatively...