Optical studies of wrapgated InP nanowires
(2019) PHYM01 20192Solid State Physics
Department of Physics
- Abstract
- This thesis describes optical spectroscopy on III-V semiconductor InP nanowires (NW) with a transparent indium-tin-oxide (ITO) gate electrode. The NWs are arranged both as vertical arrays with a wrap all around gate and as single lateral NWs with an omega-shaped gate for increased electrostatic effect.
The transparent ITO gate allows optical access with probing lasers in a 4 K He-cryostat while controlling the electrostatic environment with the gate. A coldfinger is constructed to provide easy access when connecting the samples in the cryostat.
Photoluminescence (PL) spectroscopy is used to investigate different effects in the NW. A large blueshift (110 meV) in peak energy is seen with increasing excitation power in p-doped samples... (More) - This thesis describes optical spectroscopy on III-V semiconductor InP nanowires (NW) with a transparent indium-tin-oxide (ITO) gate electrode. The NWs are arranged both as vertical arrays with a wrap all around gate and as single lateral NWs with an omega-shaped gate for increased electrostatic effect.
The transparent ITO gate allows optical access with probing lasers in a 4 K He-cryostat while controlling the electrostatic environment with the gate. A coldfinger is constructed to provide easy access when connecting the samples in the cryostat.
Photoluminescence (PL) spectroscopy is used to investigate different effects in the NW. A large blueshift (110 meV) in peak energy is seen with increasing excitation power in p-doped samples but only a small shift of 10 meV is seen in n-doped. A model is proposed where this is explained with statefilling and the effective mass being different in the conduction band compared to the valence band.
A model by Chia and LaPierre is implemented and expanded to gate bias. It uses density of interface traps ($D_{it}$) to explain how the band bending and depletion in the NW changes with radius, surface defects and bias. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8996814
- author
- Torstensson, Henrik LU
- supervisor
-
- Dan Hessman LU
- organization
- course
- PHYM01 20192
- year
- 2019
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Nanowire, InP, ITO, wrapgate, photoluminescence, interface states.
- language
- English
- id
- 8996814
- date added to LUP
- 2019-10-23 14:33:08
- date last changed
- 2019-10-23 14:33:08
@misc{8996814,
abstract = {{This thesis describes optical spectroscopy on III-V semiconductor InP nanowires (NW) with a transparent indium-tin-oxide (ITO) gate electrode. The NWs are arranged both as vertical arrays with a wrap all around gate and as single lateral NWs with an omega-shaped gate for increased electrostatic effect.
The transparent ITO gate allows optical access with probing lasers in a 4 K He-cryostat while controlling the electrostatic environment with the gate. A coldfinger is constructed to provide easy access when connecting the samples in the cryostat.
Photoluminescence (PL) spectroscopy is used to investigate different effects in the NW. A large blueshift (110 meV) in peak energy is seen with increasing excitation power in p-doped samples but only a small shift of 10 meV is seen in n-doped. A model is proposed where this is explained with statefilling and the effective mass being different in the conduction band compared to the valence band.
A model by Chia and LaPierre is implemented and expanded to gate bias. It uses density of interface traps ($D_{it}$) to explain how the band bending and depletion in the NW changes with radius, surface defects and bias.}},
author = {{Torstensson, Henrik}},
language = {{eng}},
note = {{Student Paper}},
title = {{Optical studies of wrapgated InP nanowires}},
year = {{2019}},
}