First Monolithic Tandem Photovoltaic-Powered Electrochromic Smart Window

1998 ◽  
Vol 507 ◽  
Author(s):  
W. Gao ◽  
S.H. Lee ◽  
Y. Xu ◽  
S. Morrison ◽  
D.K. Benson ◽  
...  
Keyword(s):  
Short Circuit ◽  
Visible Spectrum ◽  
Short Circuit Current ◽  
Optical Transmittance ◽  
Open Circuit ◽  
Operating Conditions ◽  
Electrochromic Device ◽  
Light Spectrum ◽  
Smart Window ◽  
Pv Cell

ABSTRACTWe report on the first monolithic, amorphous-silicon-based, photovoltaic-powered electrochromic window coating. The coating employs a wide bandgap a-Sil-xCx:H n-i-p photovoltaic (PV) cell as a semitransparent power supply, and a LiyWO3/LiAlF4/V205 electrochromic (EC) device as an optical-transmittance modulator. The EC device is deposited directly on top of a PV device that coats a glass substrate.The a-Sil-xCx:H PV cell has a Tauc gap of 2.2 eV and a transmittance of 60 to 80% over a large portion of the visible light spectrum. We reduced the thickness of the device to about 600 Å while maintaining a 1-sun open-circuit voltage of 0.9 V and short-circuit current of 2 mA/cm2.Our prototype 16 cm2 PV/EC device modulates the transmittance by more than 60% over a large portion of the visible spectrum. The coloring and bleaching times of the electrochromic device are approximately 1 minute under normal operating conditions (±1 volt).

scholarly journals Magnetic coupling coefficient determination of IPT systems under operating conditions

2014 ◽  
Vol 1 (2) ◽  
pp. 83-86 ◽  
Author(s):  
A. Abdolkhani ◽  
A.P. Hu
Keyword(s):  
Real Time ◽  
Coupling Coefficient ◽  
Short Circuit ◽  
Magnetic Coupling ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Operating Conditions ◽  
Quality Factors ◽  
Coupling Condition ◽  
Coupled Coils

This study presents a method of determining the magnetic coupling coefficient of inductive power transfer (IPT) systems under real-time operating conditions by measuring the open-circuit voltage and short-circuit current of coupled coils. Besides the theoretical analysis, the proposed method is verified by finite elements simulation and practical evaluation. Both simulation and experimental results have demonstrated that the proposed method can determine the coupling coefficient of both closely and loosely coupled coils with high-quality factors. The method can be used for online monitoring of the coupling condition and real-time power flow controller design of IPT systems.

scholarly journals Photovoltaic Cell and Module I-V Characteristic Approximation Using Bézier Curves

2018 ◽  
Author(s):  
Roland Szabo ◽  
Aurel Gontean
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Photovoltaic Cell ◽  
Open Circuit ◽  
Maximum Power ◽  
Shunt Resistance ◽  
First Case ◽  
Novel Approach ◽  
Pv Cell ◽  
Different Temperatures

The aim of this work is to introduce new ways to model the I-V characteristic of a PV cell or PV module using straight lines and Bézier curves. This is a complete novel approach, Bézier curves being previously used mainly for computer graphics. The I-V characteristic is divided in three sections, modeled with lines and a quadratic Bézier curve in the first case and with three cubic Bézier curves in the second case. The result proves to be accurate and relies on the fundamental points usually present in the PV cell datasheets: Voc (the open circuit voltage), Isc (the short circuit current), Vmp (the maximum power corresponding voltage) and Imp (the maximum power corresponding current) and the parasitic resistances Rsh0 (shunt resistance at Isc) and Rs0 (series resistance at Voc). The proposed algorithm completely defines all the implied control points and the error is analyzed. The proposed method is validated for different temperatures and irradiances. The model is finally compared and validated using the least squares fitting method.

Fabrication and Testing of Dye-Sensitized Solar Cell

2013 ◽  
Vol 771 ◽  
pp. 121-131
Author(s):  
Devi T. Rajalakshmi ◽  
R. Velavan
Keyword(s):  
Titanium Dioxide Nanoparticles ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Visible Spectrum ◽  
Cell Voltage ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Ultraviolet Region ◽  
Dye Sensitized

In Dye-Sensitized Solar Cells (DSSC), the selection of the material used for the fabrication process plays a vital role in determining the performance of the cell. The fabrication and characterization of DSSC with Ruthenizer 620-1H3TBA also known as N749 or black dye as charge transfer sensitizer is discussed in this paper. The black dye exhibits a higher absorbance throughout the entire range of visible spectrum with a peak absorbance at 620 nm and also a good absorbance in ultraviolet region. The cell thus fabricated, with cell area 2.0 cm x 2.1 cm and 487.44 μm thick coating of Titanium dioxide nanoparticles, exhibits an open circuit cell voltage of 0.61 V and short circuit current of 48 μA. Further the morphological characterization of DSSC is carried out and the results were analysed.

scholarly journals Photovoltaic Cell and Module I-V Characteristic Approximation Using Bézier Curves

2018 ◽  
Author(s):  
Roland Szabo ◽  
Aurel Gontean
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Photovoltaic Cell ◽  
Open Circuit ◽  
Maximum Power ◽  
Shunt Resistance ◽  
First Case ◽  
Novel Approach ◽  
Pv Cell ◽  
Straight Lines

The aim of this work is to introduce new ways to model the I-V characteristic of a PV cell or PV module using straight lines and Bézier curves. This is a complete novel approach, Bézier curves being previously used mainly for computer graphics. The I-V characteristic is divided in three sections, modeled with lines and a quadratic Bézier curve in the first case and with three cubic Bézier curves in the second case. The result proves to be accurate and relies on the fundamental points usually present in the PV cell datasheets: Voc (the open circuit voltage), Isc (the short circuit current), Vmp (the maximum power corresponding voltage) and Imp (the maximum power corresponding current) and the parasitic resistances Rsh0 (shunt resistance at Isc) and Rs0 (series resistance at Voc). The proposed algorithm completely defines all the implied control points and the error is analyzed. The temperature and irradiance influence is also analyzed. The model is also compared using the least squares fitting method. The final validation shows how to use Bézier cubic curves to accurately represent the I-V curves of an extensive range of PV cells and arrays.

scholarly journals THREE-DIODE MODEL AND SIMULATION OF PHOTOVOLTAIC (PV) CELLS

2019 ◽  
pp. 108-116
Keyword(s):  
Cell Model ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Photovoltaic Cell ◽  
Open Circuit ◽  
Cell Parameters ◽  
Model And Simulation ◽  
Pv Cell ◽  
Mathematical Equations ◽  
Model Equations

Existing empirical solar cell models use one or two diodes. As the number of diodes in a model increases, the mathematical complexity in deriving model equations also increases. In this paper, a photovoltaic cell is modeled using three diodes. Non-linear mathematical equations governing the I-V and P-V characteristics are summarized and simulated using Matlab looping iterative method. All simulations were performed in Matlab. Comparison is made between all models (one, two and three-diode) for design verification. Results obtained show that as the number of diodes increases in a PV cell model, the open circuit voltage and maximum power decreases for a given set of PV cell parameters. The short circuit current remained at a fixed value irrespective of the number of diodes.

scholarly journals CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Early Years ◽  
Solar Cell Efficiency ◽  
Cell Efficiency

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.

scholarly journals GaInP/GaAs/poly-Si Multi-Junction Solar Cells by in Metal Balls Bonding

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 726
Author(s):  
Ray-Hua Horng ◽  
Yu-Cheng Kao ◽  
Apoorva Sood ◽  
Po-Liang Liu ◽  
Wei-Cheng Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Low Temperature ◽  
Triple Junction ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Metal Line ◽  
Solar Simulator ◽  
Junction Solar Cell

In this study, a mechanical stacking technique has been used to bond together the GaInP/GaAs and poly-silicon (Si) solar wafers. A GaInP/GaAs/poly-Si triple-junction solar cell has mechanically stacked using a low-temperature bonding process which involves micro metal In balls on a metal line using a high-optical-transmission spin-coated glue material. Current–voltage measurements of the GaInP/GaAs/poly-Si triple-junction solar cells have carried out at room temperature both in the dark and under 1 sun with 100 mW/cm2 power density using a solar simulator. The GaInP/GaAs/poly-Si triple-junction solar cell has reached an efficiency of 24.5% with an open-circuit voltage of 2.68 V, a short-circuit current density of 12.39 mA/cm2, and a fill-factor of 73.8%. This study demonstrates a great potential for the low-temperature micro-metal-ball mechanical stacking technique to achieve high conversion efficiency for solar cells with three or more junctions.

scholarly journals Photocurrent density and electrical properties of Bi0.5Na0.5TiO3-BaNi0.5Nb0.5O3 ceramics

2021 ◽  
Author(s):  
Mingqiang Zhong ◽  
Qin Feng ◽  
Changlai Yuan ◽  
Xiao Liu ◽  
Baohua Zhu ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Photovoltaic Effect ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Photocurrent Density ◽  
Open Circuit ◽  
Light Conditions ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
X Ray

AbstractIn this work, the (1−x)Bi0.5Na0.5TiO3-xBaNi0.5Nb0.5O3 (BNT-BNN; 0.00 ⩽ x ⩽ 0.20) ceramics were prepared via a high-temperature solid-state method. The crystalline structures, photovoltaic effect, and electrical properties of the ceramics were investigated. According to X-ray diffraction, the system shows a single perovskite structure. The samples show the normal ferroelectric loops. With the increase of BNN content, the remnant polarization (Pr) and coercive field (Ec) decrease gradually. The optical band gap of the samples narrows from 3.10 to 2.27 eV. The conductive species of grains and grain boundaries in the ceramics are ascribed to the double ionized oxygen vacancies. The open-circuit voltage (Voc) of ∼15.7 V and short-circuit current (Jsc) of ∼1450 nA/cm2 are obtained in the 0.95BNT-0.05BNN ceramic under 1 sun illumination (AM1.5G, 100 mW/cm2). A larger Voc of 23 V and a higher Jsc of 5500 nA/cm2 are achieved at the poling field of 60 kV/cm under the same light conditions. The study shows this system has great application prospects in the photovoltaic field.

scholarly journals Ultrathin Cu(In,Ga)Se2 Solar Cells with Ag/AlOx Passivating Back Reflector

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4268
Author(s):  
Jessica de Wild ◽  
Gizem Birant ◽  
Guy Brammertz ◽  
Marc Meuris ◽  
Jef Poortmans ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Solar Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Electron Microscopic ◽  
Current Increase ◽  
Time Resolved ◽  
Cigs Solar Cells

Ultrathin Cu(In,Ga)Se2 (CIGS) absorber layers of 550 nm were grown on Ag/AlOx stacks. The addition of the stack resulted in solar cells with improved fill factor, open circuit voltage and short circuit current density. The efficiency was increased from 7% to almost 12%. Photoluminescence (PL) and time resolved PL were improved, which was attributed to the passivating properties of AlOx. A current increase of almost 2 mA/cm2 was measured, due to increased light scattering and surface roughness. With time of flight—secondary ion mass spectroscopy, the elemental profiles were measured. It was found that the Ag is incorporated through the whole CIGS layer. Secondary electron microscopic images of the Mo back revealed residuals of the Ag/AlOx stack, which was confirmed by energy dispersive X-ray spectroscopy measurements. It is assumed to induce the increased surface roughness and scattering properties. At the front, large stains are visible for the cells with the Ag/AlOx back contact. An ammonia sulfide etching step was therefore applied on the bare absorber improving the efficiency further to 11.7%. It shows the potential of utilizing an Ag/AlOx stack at the back to improve both electrical and optical properties of ultrathin CIGS solar cells.

Enhancement of the performance of CdS/CdTe heterojunction solar cell using TiO2/ZnO bi-layer ARC and V2O5 BSF layers: A simulation approach

2020 ◽  
Vol 92 (2) ◽  
pp. 20901
Author(s):  
Abdul Kuddus ◽  
Md. Ferdous Rahman ◽  
Jaker Hossain ◽  
Abu Bakar Md. Ismail
Keyword(s):  
Solar Cell ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Heterojunction Solar Cell ◽  
Back Surface ◽  
Heterojunction Solar Cells

This article presents the role of Bi-layer anti-reflection coating (ARC) of TiO2/ZnO and back surface field (BSF) of V2O5 for improving the photovoltaic performance of Cadmium Sulfide (CdS) and Cadmium Telluride (CdTe) based heterojunction solar cells (HJSCs). The simulation was performed at different concentrations, thickness, defect densities of each active materials and working temperatures to optimize the most excellent structure and working conditions for achieving the highest cell performance using obtained optical and electrical parameters value from the experimental investigation on spin-coated CdS, CdTe, ZnO, TiO2 and V2O5 thin films deposited on the glass substrate. The simulation results reveal that the designed CdS/CdTe based heterojunction cell offers the highest efficiency, η of ∼25% with an enhanced open-circuit voltage, Voc of 0.811 V, short circuit current density, Jsc of 38.51 mA cm−2, fill factor, FF of 80% with bi-layer ARC and BSF. Moreover, it appears that the TiO2/ZnO bi-layer ARC, as well as ETL and V2O5 as BSF, could be highly promising materials of choice for CdS/CdTe based heterojunction solar cell.

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