Light interaction with nano-materials
(2014) FYSM60 20141Department of Physics
Solid State Physics
- Abstract
- "There is a crack in everything. That's how light gets in." With two simple sentences the famous poet Leonard Cohen describes his perception on how light interacts with matter. This thesis work will try to give a more precise and detailed description of the interaction between light and nano-materials that maybe is going to lose some of the magic that poetry has but this will be compensated by the magic of revealing how nature works through the physical phenomena.
The system that is studied in the current thesis consists of vertical periodic arrays of core-shell nanowires and the objective of the thesis is to simulate how the light interacts with this structure. The way to simulate the light propagation inside the system is to... (More) - "There is a crack in everything. That's how light gets in." With two simple sentences the famous poet Leonard Cohen describes his perception on how light interacts with matter. This thesis work will try to give a more precise and detailed description of the interaction between light and nano-materials that maybe is going to lose some of the magic that poetry has but this will be compensated by the magic of revealing how nature works through the physical phenomena.
The system that is studied in the current thesis consists of vertical periodic arrays of core-shell nanowires and the objective of the thesis is to simulate how the light interacts with this structure. The way to simulate the light propagation inside the system is to solve a set of differential equations, the well-known Maxwell equations. By solving these equations it becomes possible to calculate very important physical properties of the nano-structure that are connected to the efficiency of two main applications: the photovoltaic devices and photo-detectors. Moreover, different geometrical properties of the nano-structure (such as the shape of the nanowires, the diameter and the length of the nanowires, the periodicity of the arrays etc.) can be altered and the system can be studied for each different case. The results of the simulations can give useful information in order to find the structure that presents higher efficiency for the applications, but also to obtain a better understanding of the physical phenomena that are connected with light interaction with nano-materials.
It becomes obvious that simulations constitute a cost efficient method to investigate which structure has the potential to be used in a future application and to point the direction of a more extensive experimental research for these particular structures. In this way the experimental research becomes more effective and focused, with lower consumption of resources and time. (Less) - Popular Abstract
- In the current thesis work the light interaction with a nano-structure is studied. Nano-structure is called a structure that consists of building cells that have size in the scale of nanometer(nm). The structure that is studied consists of vertical periodic arrays of core-shell nanowires, which are nanowires with a cylindrical core of a semiconductor material and a shell with a different semiconductor around them.
The mechanisms that govern the light interaction with nano-materials are different than the mechanisms that exist in the light interaction with bulk materials. The light waves get trapped inside the nano-structure and this results in the enhancement of the absorption. Thus, these nano-structures appear very promising for... (More) - In the current thesis work the light interaction with a nano-structure is studied. Nano-structure is called a structure that consists of building cells that have size in the scale of nanometer(nm). The structure that is studied consists of vertical periodic arrays of core-shell nanowires, which are nanowires with a cylindrical core of a semiconductor material and a shell with a different semiconductor around them.
The mechanisms that govern the light interaction with nano-materials are different than the mechanisms that exist in the light interaction with bulk materials. The light waves get trapped inside the nano-structure and this results in the enhancement of the absorption. Thus, these nano-structures appear very promising for applications in photovoltaic and photodetector devices.
More specifically, by solving a set of equations, known as Maxwell equations, it becomes possible to simulate the propagation of light inside the structure. These calculations provide important data and by interpreting this information we obtain a more profound understanding of the new physical phenomena that arise. Additionally, we run the simulations for different geometries of the nano-strucure and, by comparing the results, the structure that presents the optimal characteristics for our applications can be chosen. Consequently, the simulations constitute a very effective method where different structures can be studied to find the most efficient one for our applications.
Similar work has been done for the normal nanowires, but there is not much information published on the core-shell nanowire arrays. The objective of this thesis is to fill in this gap in bibliography and study the light interaction with these structures. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/4668294
- author
- Tsopanidis, Stylianos LU
- supervisor
-
- Hongqi Xu LU
- organization
- course
- FYSM60 20141
- year
- 2014
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Fourier Modal Method, Scattering Matrix Method, Electromagnetism, Maxwell equations
- language
- English
- id
- 4668294
- date added to LUP
- 2014-10-09 09:52:58
- date last changed
- 2014-10-22 09:58:38
@misc{4668294,
abstract = {{[i] "There is a crack in everything. That's how light gets in."[/i] With two simple sentences the famous poet Leonard Cohen describes his perception on how light interacts with matter. This thesis work will try to give a more precise and detailed description of the interaction between light and nano-materials that maybe is going to lose some of the magic that poetry has but this will be compensated by the magic of revealing how nature works through the physical phenomena.
The system that is studied in the current thesis consists of vertical periodic arrays of core-shell nanowires and the objective of the thesis is to simulate how the light interacts with this structure. The way to simulate the light propagation inside the system is to solve a set of differential equations, the well-known Maxwell equations. By solving these equations it becomes possible to calculate very important physical properties of the nano-structure that are connected to the efficiency of two main applications: the photovoltaic devices and photo-detectors. Moreover, different geometrical properties of the nano-structure (such as the shape of the nanowires, the diameter and the length of the nanowires, the periodicity of the arrays etc.) can be altered and the system can be studied for each different case. The results of the simulations can give useful information in order to find the structure that presents higher efficiency for the applications, but also to obtain a better understanding of the physical phenomena that are connected with light interaction with nano-materials.
It becomes obvious that simulations constitute a cost efficient method to investigate which structure has the potential to be used in a future application and to point the direction of a more extensive experimental research for these particular structures. In this way the experimental research becomes more effective and focused, with lower consumption of resources and time.}},
author = {{Tsopanidis, Stylianos}},
language = {{eng}},
note = {{Student Paper}},
title = {{Light interaction with nano-materials}},
year = {{2014}},
}