Dr James Gott

Background

I graduated from the University of Warwick in 2016 with a BSc MPhys in Physics. I then worked on my PhD project, "Atomic Resolution Structure and Spectroscopy of Semiconducting Nanowires", under the supervision of Prof. Ana Sanchez and Prof. Richard Beanland.

I am currently working as a postdoc on the project "Electric Fields by 4D scanning transmission electron microscopy" led by Prof. Ana Sanchez, Prof. Richard Beanland, Prof. Marin Alexe and Dr Vishal Shah.

Interests

My current work uses advanced electron microscopy techniques to study a range of nano materials.

My PhD work looked to characterise III-V semiconducting nanowires (NWs). Systems examined included GaAsxP1-x/GaAs core-shell structures, quantum dot structures and quantum well structures.

Techniques used include: STEM (BF, ABF, ADF, and HAADF), TEM, SEM, EDX, EELS, FIB (for sample preparation), microtome (sample preparation), and cathodoluminescence (CL). I also have experience preparing samples for and using DENS Solutions heating and heating/biasing in-situ MEMS chips.

Examples

This work describes previously undiscovered topologically protected line defects with null Burgers vector that, unlike dislocations, are stable in nanoscale crystals. Defects are analysed using atomic resolution imaging.

Stable Defects in Semiconductor Nanowires

This work analyzes the stability of null Burgers vector defects in self-catalysed III-V nanowires. Defect behaviour is observed using in situ aberration corrected STEM.

Defect Dynamics in Self-Catalyzed III-V Semiconductor Nanowires

Publications

"Ferroelectric incommensurate spin crystals"
D. Rusu, J.J.P. Peters, T.P.A. Hase, J.A. Gott, G.A.A. Nisbet, J. Strempfer, D. Haskel, S.D. Seddon, R. Beanland, A.M. Sanchez and M. Alexe, Nature 602, 240 (2022)

"Defects in Self-Catalysed III-V Nanowires"
J.A. Gott, Springer (2022)

"Multiple radial phosphorus segregations in GaAsP core-shell nanowires"
H.A. Fonseka, Y. Zhang, J.A. Gott, R. Beanland, H. Liu and A.M. Sanchez, Nano Research 14, 157 (2021)

"GaAsP Nanowires Containing Intentional and Self-Forming Quantum Dots"
H.A. Fonseka, A.V. Velichko, Y. Zhang, G.D. Davis, J.A. Gott, T. Godde, A.M. Sanchez, R. Beanland, H. Liu and D.J. Mowbray, Proc. SPIE 11291, 112910J (2020)

"Defect Dynamics in Self-Catalyzed III–V Semiconductor Nanowires"
J.A. Gott, R. Beanland, J.J.P. Peters, Y. Zhang, H. Liu and A.M. Sanchez, Nanoletters 19, 4574 (2019)

"Self-Formed Quantum Wires and Dots in GaAsP–GaAsP Core–Shell Nanowires"
H.A. Fonseka, A.V. Velichko, J.A. Gott, G.D. Davis, R. Beanland, H. Liu, D.J. Mowbray and A.M Sanchez, Nanoletters 19, 4158 (2019)

"Highly Strained III–V–V Coaxial Nanowire Quantum Wells with Strong Carrier Confinement"
Y. Zhang, G. Davis, H.A. Fonseka, A.V. Velichko, A. Gustafsson, T. Godde, D. Saxena, M. Aagesen, P.W. Parkinson, J.A. Gott, S. Huo, A.M. Sanchez, D.J. Mowbray and H. Liu, ACS Nano 13, 5931 (2019)

"Growth and Fabrication of High‐Quality Single Nanowire Devices with Radial p‐i‐n Junctions"
Y. Zhang, A.M. Sanchez, M. Aagesen, S. Huo, H.A. Fonseka, J.A. Gott, D. Kim, X. Yu, X. Chen, J. Xu, T. Li, H. Zeng, G. Boras, and H. Liu, Small 15, 1803684 (2018)

"Hybrid III–V/IV Nanowires: High-Quality Ge Shell Epitaxy on GaAs Cores"
H. Zeng, X. Yu, H.A. Fonseka, J.A. Gott, M. Tang, Y. Zhang, G. Boras, J. Xu, A.M Sanchez, and H. Liu, Nanoletters 18, 6397 (2018)

"Stable Defects in Semiconductor Nanowires"
A.M. Sanchez, J.A. Gott, H.A. Fonseka, Y. Zhang, H. Liu and R. Beanland , Nanoletters 18, 3081 (2018)

"Stable Step Facets in III-V Semiconducting Nanowires"
J.A. Gott, R. Beanland, H.A. Fonseka, Y. Zhang, H. Liu and A.M. Sanchez, Microscopy and Analysis Magazine 33, 12 (2017)

"Growth of Pure Zinc-Blende GaAs(P) Core–Shell Nanowires with Highly Regular Morphology"
Y. Zhang, H. A. Fonseka, M. Aagesen, J. A. Gott, A. M. Sanchez, J. Wu, D. Kim, P. Jurczak, S. Huo∥, and H. Liu, Nanoletters 17, 4946 (2017)

Conferences

MSM 2017, Oxford, UK (Poster) - "Stable Linear Defects in GaAsP Core-Shell Nanowires"

MMC 2017, Manchester, UK (Flash talk + Poster) - "Interface Analysis of GaAsP/GaAs Axial Nanowire Quantum Dots"

EMAG 2018, Warwick, UK (Poster) - "III-V Nanowires with Stable Defects at High Temperatures"

MSM 2019, Cambridge, UK (Talk + Poster) - "In-Situ Observation of Σ3 {112} Twin Boundary Motion at Atomic Resolution in III-V Nanowires"

E-MRS Spring Meeting 2019, Nice, France (Talk) - "In-Situ Observation of Σ3 {112} Twin Boundary Motion at Atomic Resolution in III-V Nanowires"

MMC 2019, Manchester, UK (Talk) - "In-Situ Observation of Σ3 {112} Twin Boundary Motion at Atomic Resolution in III-V Nanowires"

MMC 2021, Online (Flash talk + Poster) - "Observing Changes in Polar Domain Structures in Ferroelectric Oxide Thin Films Using Atomic Resolution In-Situ Electron Microscopy"