Transcript Reza Arkani - Physics - Lancaster University

A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Modelling Dilute Nitride Semiconductors
(PROMIS Mid-term Review Meeting)
Reza Arkani
Supervisor: Eoin O’Reilly
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
My specific background
BSc in Electrical Engineering
(Magneto-therapy)
Karaj University
MSc in Photonics
(Performance Enhancement of
Thin-film Silicon Solar Cells Using
Photonic Crystals)
Laser & Plasma Research Institute
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
My specific background
I joined Tyndall National Institute on
November 2015 to start my research
in Photonics Theory Group.
Demonstrating undergraduate
module courses in Department of
Physics, University College Cork
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
My role in PROMIS project
Modelling of dilute nitride quantum wells and quantum dots
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Dilute nitride semiconductors
- In dilute nitride materials,
localised Nitrogen resonant
states reduce the band gap
energy, and effectively cause
the conduction band to split into
two non-parabolic sub-bands
leading to flexible wavelength
tailoring.
- Band Anti-Crossing (BAC)
model provides a good basis to
understand the electronic
properties of nitride alloys.
Dispersion relation for GaN0.005As0.995
calculated by BAC model
Tomić, S., et al. , Physical Review B 69.24 (2004): 245305.
Shan, w., et. al. , Physical Review Letters 82 (1999): 1221.
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Introduction to S/PHI/nX
S/PHI/nX
is a software package
which uses continuum
elasticity
theory
and
multiband k.p model for
opto-electronic properties
of
quantum
nanostructures.
-
2-band BAC:
for conduction band (CB)
-
10-band BAC:
for valence band (VB)
O. Marquardt, “Tutorial based on S/PHI/nX 2. 0. 2”, 2012
Gladysiewicz, M., et. al., Journal of Applied Physics 113.6 (2013): 063514.
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Quantum well calculation by 2-band &
10-band BAC model
Bold lines: 2-band BAC
Dashed lines: 10-band BAC
Well width dependence of
the transition energies of GaN0.02As0.98
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Simulation of strained QW structures
InGaAsN
GaAs
CB = 1.42
Hydrostatic
component
Biaxial
strain
In0.35Ga0.65As0.98N0.02
GaAs
GaAs
CB = 1.14
δECBhy
VB = 0.11 δE hy
VB
VB = 0
SO = -0.25
SO = -0.34
ΔEC = 0.29
ηaxhh
HH = 0.10
ηaxlh
LH = 0.08
Energy (eV)
Energy (eV)
CB = 1.04
e1–hh1= 1.103
(1.13 μm)
ΔEV = 0.10
δEVBhy
ηaxso
e1 = 0.063
Eg = 1.42
hh1 = 0.006
SO = -0.27
Sketch of strain-related shifts in
CB and VB of In0.35Ga0.65As0.98N0.02/GaAs.
Confinement potential for 8 nm wide
In0.35Ga0.65As0.98N0.02/GaAs QW.
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Simulation of Quantum Dots
6 nm
6 nm
6 nm
Sketch of a GaN0.02As0.98/GaAs QD
E = 1.24 eV
E = 1.33 eV
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Summary
• Studies on BAC model
• Learning how to use S/PHI/nX as a powerful tool for
quantum nano-structures calculations
• QW band structure calculations using both 2-band &
10-band BAC model
• QD band structure calculations using 2-band BAC
model
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Skills acquired
• Coding in Matlab and C
• Application and use of freeware S/PHI/nX, including
testing and learning how to deal with the bugs
• Attended three courses in UCC:
- Advanced Computational Physics
- Advanced Condensed Matter Physics
- Post-graduate Teaching & Demonstrating Module
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Outputs
Poster presentation in
Tyndall Poster Competition,
July 2016
Poster presentation in the MBE
Conference 2016 (as a part of
PROMIS), September 2016
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Outlook
Future works:
• Optimising the electronic and optical properties of GaSbN
QD’s for CPV solar cells grown by Lancaster University (WP3)
• Designing and optimising the emission characteristics of
Type-II InAsSbN/InAs/AlAsSb structures grown by Lancaster
University for mid-IR LED applications (WP4)
• Modelling hydrogenated dilute nitride semiconductors (WP1)
Aspirations:
• Industry/academic position in which I can use my knowledge,
specifically optimisation studies in Photonics
A Marie Skłodowska-Curie Initial
Training Network
Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics
Thank you for your attention