PROMIS A Marie SkodowskaCurie Initial Training Network Postgraduate

PROMIS 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

PROMIS 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

PROMIS 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

PROMIS 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

PROMIS 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 Ga. N 0. 005 As 0. 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.

PROMIS A Marie Skłodowska-Curie Initial Training Network Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics Introduction to S/PHI/n. X 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/n. X 2. 0. 2”, 2012 Gladysiewicz, M. , et. al. , Journal of Applied Physics 113. 6 (2013): 063514.

PROMIS 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 Ga. N 0. 02 As 0. 98

PROMIS A Marie Skłodowska-Curie Initial Training Network Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics Simulation of strained QW structures In. Ga. As. N Ga. As CB = 1. 42 Hydrostatic component Biaxial strain In 0. 35 Ga 0. 65 As 0. 98 N 0. 02 Ga. As CB = 1. 14 VB = 0. 11 δECBhy δEVBhy VB = 0 SO = -0. 25 SO = -0. 34 ΔEC = 0. 29 ηaxhh HH = 0. 10 ηaxlh LH = 0. 08 Energy (e. V) CB = 1. 04 e 1–hh 1= 1. 103 (1. 13 μm) ΔEV = 0. 10 δEVBhy ηaxso e 1 = 0. 063 Eg = 1. 42 hh 1 = 0. 006 SO = -0. 27 Sketch of strain-related shifts in CB and VB of In 0. 35 Ga 0. 65 As 0. 98 N 0. 02/Ga. As. Confinement potential for 8 nm wide In 0. 35 Ga 0. 65 As 0. 98 N 0. 02/Ga. As QW.

PROMIS A Marie Skłodowska-Curie Initial Training Network Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics Simulation of Quantum Dots 6 nm Sketch of a Ga. N 0. 02 As 0. 98/Ga. As QD E = 1. 24 e. V E = 1. 33 e. V

PROMIS 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/n. X 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

PROMIS 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/n. X, 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

PROMIS 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

PROMIS 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 Ga. Sb. N QD’s for CPV solar cells grown by Lancaster University (WP 3) • Designing and optimising the emission characteristics of Type -II In. As. Sb. N/In. As/Al. As. Sb structures grown by Lancaster University for mid-IR LED applications (WP 4) • Modelling hydrogenated dilute nitride semiconductors (WP 1) Aspirations: • Industry/academic position in which I can use my knowledge, specifically optimisation studies in Photonics

PROMIS A Marie Skłodowska-Curie Initial Training Network Postgraduate Research on Dilute Metamorphic Nanostructures and Metamaterials in Semiconductor Photonics Thank you for your attention