CdTe/PbTe Superlattice Energy Bands Analysis Using k.p Method

2015 ◽  
Vol 1105 ◽  
pp. 127-130
Author(s):  
Amal Kabalan ◽  
Pritpal Singh
Keyword(s):  
Perturbation Theory ◽  
Solar Cell ◽  
Heavy Hole ◽  
Light Hole ◽  
Maximum Efficiency ◽  
Energy Bands ◽  
Superlattice Structure ◽  
Optical Bandgaps ◽  
The Relationship ◽  
K.P Method

A model based on the k.p perturbation theory to compute the energy bands in a CdTe/PbTe superlattice structure is developed. The model uses the dispersion relations for the heavy hole, light hole and the split off bands to compute the effective bandgap in a CdTe/PbTe superlattice structure. Given a certain thickness of the layers composing the superlattice the model computes the effective bandgap. This model will be used towards understanding the relationship between film thickness and optical bandgaps in a CdTe/PbTe superlattice. The end goal is to tailor the optical bandgap of a CdTe/PbTe superlattice to result in maximum efficiency when used in a solar cell.

scholarly journals Valence Band Mixing in GaAs/AlGaAs Quantum Wells Adjacent to Self-Assembled InAlAs Antidots

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Takuya Kawazu
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Valence Band ◽  
Energy Barrier ◽  
Heavy Hole ◽  
Electronic States ◽  
Light Hole ◽  
Photoluminescence Excitation ◽  
Band Mixing ◽  
Valence Band Mixing

Optical properties of GaAs/AlGaAs quantum wells (QWs) in the vicinity of InAlAs quantum dots (QDs) were studied and compared with a theoretical model to clarify how the QD strain affects the electronic states in the nearby QW. In0.4Al0.6As QDs are embedded at the top of the QWs; the QD layer acts as a source of strain as well as an energy barrier. Photoluminescence excitation (PLE) measurements showed that the QD formation leads to the increase in the ratio Ie-lh/Ie-hh of the PLE intensities for the light hole (lh) and the heavy hole (hh), indicating the presence of the valence band mixing. We also theoretically calculated the hh-lh mixing in the QW due to the nearby QD strain and evaluated the PLE ratio Ie-lh/Ie-hh.

scholarly journals Electricity market efficiency and voltage stability

2021 ◽  
Author(s):  
Ayman Helmy Mostafa Elkasrawy
Keyword(s):  
Power System ◽  
Market Efficiency ◽  
Electricity Markets ◽  
Electricity Market ◽  
Voltage Stability ◽  
Electric Power System ◽  
Maximum Efficiency ◽  
Best Interest ◽  
The Relationship ◽  
System Layout

Several electricity markets were created in the last two decades by deregulation and restructuring vertically integrated utilities. In order to serve the best interest of participating entities, it is important to operate electricity markets at their maximum efficiency. In most cases, electricity markets were formed to operate on existing physical power systems that had evolved over several decades as vertically integrated utilities. Location of generating stations, large urban load centers and enabling transmission systems were unique to every power system and followed the 'lay of the land'. Depending upon a power system layout, voltage stability and margin to voltage collapse are unique to it. While an electricity market is to be operated efficiently, its optimal generation schedule to supply energy through an electric power system has to be reliable and meet the strict standards including those that relate to voltage stability. This work elicits the relationship between market efficiency and voltage stability. To this end, a formulation and a solution algorithm are presented. Two contrasting 5-bus cases illustrate how the transmission system layout influences the relationship between voltage stability and market efficiency. The IEEE 118-bus system is also used to illustrate this relationship.

Exciton binding energies in GaAs films on AlxGa1−xAs substrates

2015 ◽  
Vol 29 (30) ◽  
pp. 1550213 ◽  
Author(s):  
Zhenhua Wu ◽  
Lei Chen ◽  
Qiang Tian
Keyword(s):  
Film Thickness ◽  
Significant Influence ◽  
Heavy Hole ◽  
Dimensional Space ◽  
Light Hole ◽  
Binding Energies ◽  
Substrate Thickness ◽  
Dimensional Approach ◽  
Anisotropic System ◽  
Gaas Films

We use the fractional–dimensional approach (FDA) to study exciton binding energies in GaAs films on [Formula: see text] substrates. In this approach, the Schrödinger equation for a given anisotropic system is solved in a noninteger-dimensional space where the interactions are assumed to occur in an isotropic effective environment. The heavy-hole and light-hole exciton binding energies are calculated as functions of the film thickness and substrate thickness. The numerical results show that both the heavy-hole and light-hole exciton binding energies decrease monotonously as the film thickness increases. When the film thickness and the substrate thickness is relatively small, the change of substrate thickness has comparatively remarkable influence on both heavy-hole and light-hole exciton binding energies. As the substrate thickness increases, both the heavy-hole and light-hole exciton binding energies increase gradually. When the film thickness or the substrate thickness is relatively large, the change of substrate thickness has no significant influence on both heavy-hole and light-hole exciton binding energies.

Solution of the Dirac Equation for the Rectilinear Periodic Motion of an Electron

1969 ◽  
Vol 24 (3) ◽  
pp. 344-349
Author(s):  
A. D. Jannussis
Keyword(s):  
Perturbation Theory ◽  
Dirac Equation ◽  
Periodic Motion ◽  
Periodic Potential ◽  
Bragg Reflection ◽  
Wave Number ◽  
Periodic Functions ◽  
Energy Bands ◽  
Energy Eigenvalues ◽  
The Hill

AbstractIn this paper the Dirac equation for a rectilinear onedimensional periodic potential is treated. It is shown that the energy eigenvalues are periodic functions of the wave number Kϰ and the continuous spectrum is split into energy bands. The end points of the energy bands are the points where the Bragg reflection takes place. These results are obtained by perturbation theory, as well as by the method of determinants, since the resulting eigenvalue equation has the form of a determinant which is similar to the Hill determinant.

scholarly journals A Frequency Locking Method for ICPT System Based on LCC/S Compensation Topology

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2626
Author(s):  
Yansong Li ◽  
Minhao Wang ◽  
Weiwei Zhang ◽  
Mengmeng Zhao ◽  
Jun Liu
Keyword(s):  
Output Power ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Maximum Efficiency ◽  
Initial Value ◽  
Frequency Locking ◽  
Inductively Coupled ◽  
Output Characteristics ◽  
The Relationship

Aiming to maximize the transmission efficiency of inductively coupled power transmission (ICPT) system with the designed output power, a frequency locking method for an ICPT system based on LCC/S compensation topology is proposed in this paper. Firstly, the relationship between compensation component Lf1 and output power was deduced by the lossless model, and the initial value of Lf1 was obtained. Then, considering the system loss, the designed output power and frequency were input into the frequency locking program, and Lf1 and other compensation parameters were dynamically tracked. At the same time, the transmission efficiency of the system was calculated, and the frequency that achieved maximum efficiency was automatically locked when the system met the requirements of the designed output power. Finally, based on the method, the output characteristics of the system were verified by experiments.

scholarly journals Probing the light hole/heavy hole switching with correlated magneto-optical spectroscopy and chemical analysis on a single quantum dot

2019 ◽  
Vol 30 (17) ◽  
pp. 175301
Author(s):  
A Artioli ◽  
P Rueda-Fonseca ◽  
K Moratis ◽  
J F Motte ◽  
F Donatini ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Quantum Dot ◽  
Optical Spectroscopy ◽  
Heavy Hole ◽  
Light Hole ◽  
Single Quantum ◽  
Single Quantum Dot

A Newly Designed ZnO/CdS/CuO:Co Solar Cell and Its Performance

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
L. Nkhaili ◽  
H. El Aakib ◽  
C.-T. Liang ◽  
A. Narjis ◽  
H. AitDads ◽  
...  
Keyword(s):  
Refractive Index ◽  
Fourier Transform ◽  
Solar Cell ◽  
Sol Gel ◽  
Rf Sputtering ◽  
Electrical Contacts ◽  
Rf Power ◽  
Energy Bands ◽  
X Ray ◽  
Silver Electrodes

Abstract In this paper, a ZnO/CdS/CuO:Co solar cell was prepared on a glass/indium oxide (ITO) substrate. First, we use RF-sputtering to deposit the window (ZnO) layer by optimizing the oxygen pressure while keeping the RF power at 200 W. Fourier transform infrared and X-ray reflectometry spectra were carried out, and it is found that 30% of O2 is the optimal percentage to obtain the best density and the best refractive index for the ZnO layer. The CdS layer was then deposited by the sol–gel method to align the energy bands, and a layer of CuO:Co with a thickness of 750 nm was deposited, also by reactive RF-sputtering technique. Finally, the electrical contacts were made by depositing circular silver electrodes. The obtained photovoltaic activity of device confirms that the aforementioned method is promising for further future optimizations.

Sign in / Sign up

Export Citation Format

Share Document