scholarly journals Diode physical-limit-bandwidth efficient rectification

2021 ◽  
Author(s):  
Babita Gyawali ◽  
Samundra Kumar Thapa ◽  
Adel Barakat ◽  
Kuniaki Yoshitomi ◽  
Ramesh Kumar Pokharel
Keyword(s):  
Conversion Efficiency ◽  
Short Circuit ◽  
Peak Efficiency ◽  
Basic Aspect ◽  
Limited Bandwidth ◽  
Existing Problems ◽  
Physical Limit ◽  
Voltage Doubler ◽  
Operating Bandwidth ◽  
Stage Matching

Abstract Generally, a conventional voltage doubler circuit possesses a large variation of its input impedance over the bandwidth, which results in limited bandwidth and low RF-dc conversion efficiency. A basic aspect for designing wideband voltage doubler rectifiers is the use of complex matching circuits to achieve decade and octave impedance and RF-dc conversion efficiency bandwidths. Still, the reported techniques till now have been accompanied by a large fluctuation of the RF-dc conversion efficiency over the operating bandwidth. In this paper, we propose a novel rectification circuit with minimal inter-stage matching that consists of a single short-circuit stub and a virtual battery, which contributes negligible losses and overcomes these existing problems. Consequently, the proposed rectifier circuit achieves a diode physical-limit-bandwidth efficient rectification. In other words, the rectification bandwidth, as well as the peak efficiency, are controlled by the length of the stub and the physical limitation of the diodes.

scholarly journals Diode physical-limit-bandwidth efficient rectification

2021 ◽  
Author(s):  
Babita Gyawali ◽  
Samundra Thapa ◽  
Adel Barakat ◽  
Kuniaki Yoshitomi ◽  
Ramesh Pokharel
Keyword(s):  
Conversion Efficiency ◽  
Short Circuit ◽  
Peak Efficiency ◽  
Basic Aspect ◽  
Limited Bandwidth ◽  
Existing Problems ◽  
Physical Limit ◽  
Voltage Doubler ◽  
Operating Bandwidth ◽  
Stage Matching

Abstract Generally, a conventional voltage doubler circuit possesses a large variation of its input impedance over the bandwidth, which results in limited bandwidth and low RF-dc conversion efficiency. A basic aspect for designing wideband voltage doubler rectifiers is the use of complex matching circuits to achieve decade and octave impedance and RF-dc conversion efficiency bandwidths. Still, the reported techniques till now have been accompanied by a large fluctuation of the RF-dc conversion efficiency over the operating bandwidth. In this paper, we propose a novel rectification circuit with minimal inter-stage matching that consists of a single short-circuit stub and a virtual battery, which contributes negligible losses and overcomes these existing problems. Consequently, the proposed rectifier circuit achieves a diode physical-limit-bandwidth efficient rectification. In other words, the rectification bandwidth, as well as the peak efficiency, are controlled by the length of the stub and the physical limitation of the diodes.

scholarly journals Analysis and design of diode physical limit bandwidth efficient rectification circuit for maximum flat efficiency, wide impedance, and efficiency bandwidths

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Babita Gyawali ◽  
Samundra K. Thapa ◽  
Adel Barakat ◽  
Kuniaki Yoshitomi ◽  
Ramesh K. Pokharel
Keyword(s):  
Conversion Efficiency ◽  
Short Circuit ◽  
Basic Aspect ◽  
Limited Bandwidth ◽  
Analysis And Design ◽  
Existing Problems ◽  
Physical Limit ◽  
Voltage Doubler ◽  
Operating Bandwidth ◽  
Stage Matching

AbstractGenerally, a conventional voltage doubler circuit possesses a large variation of its input impedance over the bandwidth, which results in limited bandwidth and low RF-dc conversion efficiency. A basic aspect for designing wideband voltage doubler rectifiers is the use of complex matching circuits to achieve decade and octave impedance and RF-dc conversion efficiency bandwidths. Still, the reported techniques till now have been accompanied by a large fluctuation of the RF-dc conversion efficiency over the operating bandwidth. In this paper, we propose a novel rectification circuit with minimal inter-stage matching that consists of a single short-circuit stub and a virtual battery, which contributes negligible losses and overcomes these existing problems. Consequently, the proposed rectifier circuit achieves a diode physical-limit-bandwidth efficient rectification. In other words, the rectification bandwidth, as well as the peak efficiency, are controlled by the length of the stub and the physical limitation of the diodes.

scholarly journals Antireflection Improvement and Junction Quality Optimization of Si/PEDOT:PSS Solar Cell with the Introduction of Dopamine@Graphene

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5986
Author(s):  
Tao Chen ◽  
Hao Guo ◽  
Leiming Yu ◽  
Tao Sun ◽  
Anran Chen ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
High Performance ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrochemical Impedance Spectra ◽  
Solar Cell Performance ◽  
Photovoltaic Conversion ◽  
Photovoltaic Conversion Efficiency

Si/PEDOT: PSS solar cell is an optional photovoltaic device owing to its promising high photovoltaic conversion efficiency (PCE) and economic manufacture process. In this work, dopamine@graphene was firstly introduced between the silicon substrate and PEDOT:PSS film for Si/PEDOT: PSS solar cell. The dopamine@graphene was proved to be effective in improving the PCE, and the influence of mechanical properties of dopamine@graphene on solar cell performance was revealed. When dopamine@graphene was incorporated into the cell preparation, the antireflection ability of the cell was enhanced within the wavelength range of 300~450 and 650~1100 nm. The enhanced antireflection ability would benefit amount of the photon-generated carriers. The electrochemical impedance spectra test revealed that the introduction of dopamine@graphene could facilitate the separation of carriers and improve the junction quality. Thus, the short-circuit current density and fill factor were both promoted, which led to the improved PCE. Meanwhile, the influence of graphene concentration on device performances was also investigated. The photovoltaic conversion efficiency would be promoted from 11.06% to 13.15% when dopamine@graphene solution with concentration 1.5 mg/mL was applied. The achievements of this study showed that the dopamine@graphene composites could be an useful materials for high-performance Si/PEDOT:PSS solar cells.

scholarly journals High performance tandem organic solar cells via a strongly infrared-absorbing narrow bandgap acceptor

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhenrong Jia ◽  
Shucheng Qin ◽  
Lei Meng ◽  
Qing Ma ◽  
Indunil Angunawela ◽  
...  
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Organic Solar Cells ◽  
High Performance ◽  
Short Circuit ◽  
Power Conversion ◽  
High Power Conversion Efficiency ◽  
Device Structure ◽  
Narrow Bandgap

AbstractTandem organic solar cells are based on the device structure monolithically connecting two solar cells to broaden overall absorption spectrum and utilize the photon energy more efficiently. Herein, we demonstrate a simple strategy of inserting a double bond between the central core and end groups of the small molecule acceptor Y6 to extend its conjugation length and absorption range. As a result, a new narrow bandgap acceptor BTPV-4F was synthesized with an optical bandgap of 1.21 eV. The single-junction devices based on BTPV-4F as acceptor achieved a power conversion efficiency of over 13.4% with a high short-circuit current density of 28.9 mA cm−2. With adopting BTPV-4F as the rear cell acceptor material, the resulting tandem devices reached a high power conversion efficiency of over 16.4% with good photostability. The results indicate that BTPV-4F is an efficient infrared-absorbing narrow bandgap acceptor and has great potential to be applied into tandem organic solar cells.

scholarly journals Over 30% efficiency bifacial 4-terminal perovskite-heterojunction silicon tandem solar cells with spectral albedo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sangho Kim ◽  
Thanh Thuy Trinh ◽  
Jinjoo Park ◽  
Duy Phong Pham ◽  
Sunhwa Lee ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Solar Spectrum ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Production Costs ◽  
White Sand ◽  
Reflected Light

AbstractWe developed and designed a bifacial four-terminal perovskite (PVK)/crystalline silicon (c-Si) heterojunction (HJ) tandem solar cell configuration albedo reflection in which the c-Si HJ bottom sub-cell absorbs the solar spectrum from both the front and rear sides (reflected light from the background such as green grass, white sand, red brick, roofing shingle, snow, etc.). Using the albedo reflection and the subsequent short-circuit current density, the conversion efficiency of the PVK-filtered c-Si HJ bottom sub-cell was improved regardless of the PVK top sub-cell properties. This approach achieved a conversion efficiency exceeding 30%, which is higher than those of both the top and bottom sub-cells. Notably, this efficiency is also greater than the Schockley–Quiesser limit of the c-Si solar cell (approximately 29.43%). The proposed approach has the potential to lower industrial solar cell production costs in the near future.

scholarly journals Effect of Core-Shell Ag@TiO2Volume Ratio on Characteristics of TiO2-Based DSSCs

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ho Chang ◽  
Chih-Hao Chen ◽  
Mu-Jung Kao ◽  
Hsin-Han Hsiao
Keyword(s):  
Conversion Efficiency ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Open Circuit ◽  
Photoelectric Conversion Efficiency ◽  
Core Shell ◽  
Photoelectric Conversion ◽  
Shell Type ◽  
Degussa P25 ◽  
Triton X

This paper aims to develop photoanode material required by dye-sensitized solar cells. The material prepared is in the form of Ag@TiO2core-shell-type nanocomposites. This material is used to replace the titanium oxide powder commonly used in general DSSCs. The prepared Ag@TiO2core-shell-type nanocomposites are mixed with Degussa P25 TiO2in different proportions. Triton X-100 is added and polyethylene glycol (PEG) at 20 wt% is used as a polymer additive. This study tests the particle size and material properties of Ag@TiO2core-shell-type nanocomposites and measures the photoelectric conversion efficiency and IPCE of DSSCs. Experimental results show that the DSSC prepared by Ag@TiO2core-shell-type nanocomposites can achieve a photoelectric conversion efficiency of 3.67%. When Ag@TiO2core-shell-type nanocomposites are mixed with P25 nanoparticles in specific proportions, and when the thickness of the photoelectrode thin film is 28 μm, the photoelectric conversion efficiency can reach 6.06%, with a fill factor of 0.52, open-circuit voltage of 0.64V, and short-circuit density of 18.22 mAcm−2. Compared to the DSSC prepared by P25 TiO2only, the photoelectric conversion efficiency can be raised by 38% under the proposed approach.

scholarly journals Dye-Sensitized Nanocrystalline ZnO Solar Cells Based on Ruthenium(II) Phendione Complexes

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Hashem Shahroosvand ◽  
Parisa Abbasi ◽  
Mohsen Ameri ◽  
Mohammad Reza Riahi Dehkordi
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Conversion Efficiency ◽  
Short Circuit ◽  
Photocurrent Density ◽  
Open Circuit ◽  
Zno Thin Film ◽  
Photovoltaic Properties ◽  
Dye Sensitized ◽  
Ft Ir

The metal complexes ( (phen)2(phendione))(PF6)2(1), [ (phen)(bpy)(phendione))(PF6)2(2), and ( (bpy)2(phendione))(PF6)2(3) (phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine and phendione = 1,10-phenanthroline-5,6-dione) have been synthesized as photo sensitizers for ZnO semiconductor in solar cells. FT-IR and absorption spectra showed the favorable interfacial binding between the dye-molecules and ZnO surface. The surface analysis and size of adsorbed dye on nanostructure ZnO were further examined with AFM and SEM. The AFM images clearly show both, the outgrowth of the complexes which are adsorbed on ZnO thin film and the depression of ZnO thin film. We have studied photovoltaic properties of dye-sensitized nanocrystalline semiconductor solar cells based on Ru phendione complexes, which gave power conversion efficiency of (η) of 1.54% under the standard AM 1.5 irradiation (100 mW cm−2) with a short-circuit photocurrent density () of 3.42 mA cm−2, an open-circuit photovoltage () of 0.622 V, and a fill factor (ff) of 0.72. Monochromatic incident photon to current conversion efficiency was 38% at 485 nm.

scholarly journals Simulation of a perovskite sandwich solar cell with the p-CZTS / p-CH3NH3PbCI3 / p-CZTS absorber layers

2021 ◽  
Vol 877 (1) ◽  
pp. 012001
Author(s):  
Marwah S Mahmood ◽  
N K Hassan
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Current Density ◽  
Short Circuit ◽  
Perovskite Solar Cells ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Current Voltage ◽  
Cell Capacitance

Abstract Perovskite solar cells attract the attention because of their unique properties in photovoltaic cells. Numerical simulation to the structure of Perovskite on p-CZTS/p-CH3NH3PbCI3/p-CZTS absorber layers is performed by using a program solar cell capacitance simulator (SCAPS-1D), with changing absorber layer thickness. The effect of thickness p-CZTS/p-CH3NH3PbCI3/p-CZTS, layers at (3.2μm, 1.8 μm, 1.1 μm) respectively are studied. The obtained results are short circuit current density (Jsc ), open circuit voltage (V oc), fill factor (F. F) and power conversion efficiency (PCE) equal to (28 mA/cm2, 0.83 v, 60.58 % and 14.25 %) respectively at 1.1 μm thickness. Our findings revealed that the dependence of current - voltage characteristics on the thickness of the absorbing layers, an increase in the amount of short circuit current density with an increase in the thickness of the absorption layers and thus led to an increase in the conversion efficiency and improvement of the cell by increasing the thickness of the absorption layers.

scholarly journals Optimization of the InGaP Top Junction of Triple Junction Solar Cell for Spatial Application

2019 ◽  
Vol 14 (1) ◽  
pp. 1-5
Author(s):  
Victor De Rezende Cunha ◽  
Daniel Neves Micha ◽  
Rudy Massami Sakamoto Kawabata ◽  
Luciana Dornelas Pinto ◽  
Mauricio Pamplona Pires ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Current Density ◽  
Triple Junction ◽  
Short Circuit ◽  
Active Material ◽  
Multiple Quantum Well ◽  
Electrical Current ◽  
Multiple Quantum ◽  
Junction Solar Cell

Electrical current mismatching is a well-known limitation of triple junction solar cells that lowers the final conversion efficiency. Several solutions have been proposed to face this issue, including the insertion of a multiple quantum well structure as the intermediate junction’s active material. With a better matching in the current among the junctions, the total current increases, thus modifying the working conditions of the overall device. In this way, the InGaP top junction needs to be optimized to such new condition. In this work, numerical simulations were carried out aiming the enlargement of the electrical current density of an InGaP pn junction to achieve the proper current matching in triple junction solar cell for spatial applications. The optimized structure has been grown in a GaAs substrate and characterized as a single junction solar cell. Although the measured short circuit current density and conversion efficiency are still well below the theoretically predicted values, processing improvement should lead to adequate cell performance.

Effect of temperature on organic Schottky barrier cells

1981 ◽  
Vol 59 (6) ◽  
pp. 727-732 ◽  
Author(s):  
Rafik O. Loutfy ◽  
Cheng-Kuo Hsiao
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Schottky Barrier ◽  
Conversion Efficiency ◽  
Organic Solar Cells ◽  
Short Circuit ◽  
Power Conversion ◽  
Open Circuit ◽  
Effect Of Temperature ◽  
Photovoltaic Properties

The effect of temperature on the photovoltaic properties of indium/metal-free phthalocyanine Schottky barrier solar cells was investigated in the range 260–350 K. In general, the short circuit photocurrent, Jsc, and fill factor, ff, increased with increasing temperature (in contrast to inorganic photocells). The device series resistance and open circuit photovoltage, Voc, decreased (similar to inorganic photocells) as temperature was raised. An increase in the overall power conversion efficiency, η, has been observed with increase of temperature. In the case of x-H2Pc, the power conversion efficiency increased by 2.5 times due to a temperature rise of 60 °C above ambient. Thus, for operation at temperatures above ambient, organic solar cells may offer a significant advantage over inorganic cells.Analysis of the variation of the photovoltage with temperature showed that the decrease in Voc is mainly due to variation injunction impedance, which is controlled by thermionic current at high temperature and ionized impurity at low temperature.

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