Light Emission Induced by Charge Carrier Diffusion in Nanowires: from Synthesis to Characterization
(2026)- Abstract
- Light-emitting diodes (LEDs) are widely applied in fields ranging from solid-state lighting and high-resolution displays to optical communication and sensing. Despite their remarkable technological development, conventional thin-film LEDs remain constrained by strain-induced defects from lattice mismatch and restricted light extraction efficiency due to total internal reflection. Exploration of alternative device geometries is motivated by these challenges.
Semiconductor nanowires (nanowires) provide a promising platform due to their nanoscale geometry, which enables axial strain relaxation and thus freedom in heterostructure design. In this work, branched nanowire architecture is introduced where lower bandgap branches are synthesized... (More) - Light-emitting diodes (LEDs) are widely applied in fields ranging from solid-state lighting and high-resolution displays to optical communication and sensing. Despite their remarkable technological development, conventional thin-film LEDs remain constrained by strain-induced defects from lattice mismatch and restricted light extraction efficiency due to total internal reflection. Exploration of alternative device geometries is motivated by these challenges.
Semiconductor nanowires (nanowires) provide a promising platform due to their nanoscale geometry, which enables axial strain relaxation and thus freedom in heterostructure design. In this work, branched nanowire architecture is introduced where lower bandgap branches are synthesized on the sidewalls of higher bandgap core nanowires, from which the concept of charge carrier diffusion-induced LEDs was experimentally demonstrated. Charge carriers injected from forward biasing the core nanowires will diffuse to the lower bandgap branches recombine and emit light there.
The work begins with the development of an efficient and controllable method for depositing Au nanoparticles on the sidewalls of core nanowires, serving as catalytic seeds for branch growth. Following successful synthesis, various material configurations were designed and integrated into LED devices to enable systematic optoelectronic characterization. Electrical and optical measurements were performed to investigate carrier transport dynamics and recombination mechanisms within the core–branch structure.
By integrating materials synthesis, device fabrication, and optoelectronic characterization, this thesis advances a versatile nanowire LED architecture that offers a new pathway toward highly tunable, efficient nanoscale light emitters for next-generation optoelectronic technologies. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/218462d8-c63a-48d3-a899-b9cef53cea92
- author
- Zhao, Yue LU
- supervisor
- opponent
-
- Dr. Tchernycheva, Maria, University of Paris-Saclay, France.
- organization
- publishing date
- 2026-05-07
- type
- Thesis
- publication status
- published
- subject
- keywords
- III-V semiconductors, nanowire, light-emitting diodes, total internal reflection
- pages
- 62 pages
- publisher
- Lund University
- defense location
- Lecture Hall Rydbergsalen, Department of Physics, Professorsgatan 1, Faculty of Engineering LTH, Lund University, Lund.
- defense date
- 2026-05-07 09:15:00
- ISBN
- 978-91-8104-961-9
- 978-91-8104-962-6
- language
- English
- LU publication?
- yes
- id
- 218462d8-c63a-48d3-a899-b9cef53cea92
- date added to LUP
- 2026-04-12 16:25:55
- date last changed
- 2026-04-24 09:59:21
@phdthesis{218462d8-c63a-48d3-a899-b9cef53cea92,
abstract = {{Light-emitting diodes (LEDs) are widely applied in fields ranging from solid-state lighting and high-resolution displays to optical communication and sensing. Despite their remarkable technological development, conventional thin-film LEDs remain constrained by strain-induced defects from lattice mismatch and restricted light extraction efficiency due to total internal reflection. Exploration of alternative device geometries is motivated by these challenges.<br/>Semiconductor nanowires (nanowires) provide a promising platform due to their nanoscale geometry, which enables axial strain relaxation and thus freedom in heterostructure design. In this work, branched nanowire architecture is introduced where lower bandgap branches are synthesized on the sidewalls of higher bandgap core nanowires, from which the concept of charge carrier diffusion-induced LEDs was experimentally demonstrated. Charge carriers injected from forward biasing the core nanowires will diffuse to the lower bandgap branches recombine and emit light there.<br/>The work begins with the development of an efficient and controllable method for depositing Au nanoparticles on the sidewalls of core nanowires, serving as catalytic seeds for branch growth. Following successful synthesis, various material configurations were designed and integrated into LED devices to enable systematic optoelectronic characterization. Electrical and optical measurements were performed to investigate carrier transport dynamics and recombination mechanisms within the core–branch structure.<br/>By integrating materials synthesis, device fabrication, and optoelectronic characterization, this thesis advances a versatile nanowire LED architecture that offers a new pathway toward highly tunable, efficient nanoscale light emitters for next-generation optoelectronic technologies.}},
author = {{Zhao, Yue}},
isbn = {{978-91-8104-961-9}},
keywords = {{III-V semiconductors; nanowire; light-emitting diodes; total internal reflection}},
language = {{eng}},
month = {{05}},
publisher = {{Lund University}},
school = {{Lund University}},
title = {{Light Emission Induced by Charge Carrier Diffusion in Nanowires: from Synthesis to Characterization}},
url = {{https://lup.lub.lu.se/search/files/247253577/YueZ_Thesis_e-nailing_ex.pdf}},
year = {{2026}},
}