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S. Pizzini 《Applied Physics A: Materials Science & Processing》2009,96(1):171-188
The availability of low-cost alternatives to electronic grade silicon has been and still is the condition for the extensive
use of photovoltaics as an efficient sun harvesting system. The first step towards this objective was positively carried out
in the 1980s and resulted in the reduction in cost and energy of the growth process using as feedstock electronic grade scraps
and a variety of solidification procedures, all of which deliver a multi-crystalline material of high photovoltaic quality.
The second step was an intense R&D activity aiming at defining and developing at lab scale a new variety of silicon, called
“solar grade” silicon, which should fulfil the requirement of both cost effectiveness and high conversion efficiency.
The third step involved and still involves the development of cost-effective technologies for the manufacture of solar grade
silicon, in alternative to the classical Siemens route, which relays, as is well-known, to the pyrolitic decomposition of
high-purity trichlorosilane and which is, also in its more advanced versions, extremely energy intensive.
Aim of this paper is to give the author’s viewpoint about some open questions concerning bulk solar silicon for PV applications
and about challenges and chances of novel feedstocks of direct metallurgical origin. 相似文献
3.
光伏阵列的输出特性受光照强度影响很大,在弱光下光伏电池的最大功率点跟踪控制算法无法达到蓄电池的充电要求。为了最大限度利用光伏阵歹tl的输出功率,采用超级电容减小光照变化对蓄电池充电的影响。针对独立光伏发电系统的特点,设计了一种有源式混合储能方案,在保证光伏电池获得最大功率跟踪的同时,也能满足蓄电池的充电要求,建立的Simulink/MATLAB仿真模型验证了该设计方案的有效性。 相似文献
4.
A sodium ion conducting composite polymer electrolyte (CPE) prepared by solution-caste technique by dispersion of an electrochemically
inert ceramic filler (SnO2) in the PEO–salt complex matrix is reported. The effect of filler concentration on morphological, electrical, electrochemical,
and mechanical stability of the CPE films has been investigated and analyzed. Composite nature of the films has been confirmed
from X-ray diffraction and scanning electron microscopy patterns. Room temperature d.c. conductivity observed as a function
of filler concentration indicates an enhancement (maximum) at 1–2 wt% filler concentration followed by another maximum at
∼10 wt% SnO2. This two-maxima feature of electrical conductivity as a function of filler concentration remains unaltered in the CPE films
even at 100 °C (i.e., after crystalline melting), suggesting an active role of the filler particles in governing electrical
transport. Substantial enhancement in the voltage stability and mechanical properties of the CPE films has been noticed on
filler dispersion. The composite polymer films have been observed to be predominantly ionic in nature with t
ion ∼ 0.99 for 1–2 wt% SnO2. However, this value gets lowered on increasing addition of SnO2 with t
ion ∼ 0.90 for 25 wt% SnO2. A calculation of ionic and electronic conductivity for 25 wt% of SnO2 film works out to be ∼2.34 × 10−6 and 2.6 × 10−7 S/cm, respectively. 相似文献
5.
《Current Applied Physics》2020,20(4):582-588
Energy storage system powered by renewable energies is a viable option to meet energy requirement without addition of carbon footprints to the environment. This study involves development of theoretical and computational models for a solar photovoltaic (PV) system coupled with a lead acid battery. The study commenced with selection of most appropriate lead acid battery and PV system for installation in a representative location in Riyadh, Kingdom of Saudi Arabia. Various technical and economic parameters were assessed and calculated by computational approach. The optimized lead acid battery was integrated with low concentration solar PV panels (CPV) followed by a feasibility study. Theoretical model was developed for the integrated system to calculate various parameters of the CPV and lead acid battery. Technical and economic assessment of this coupled unit was calculated using a theoretical approach. The developed model was then subjected to computational approach for verification and validation analysis of the integrated system. The detailed assessment of batteries and integrated system show the applicability of this system in Riyadh region. The research will be extended to develop energy storage systems for remote areas using lead acid batteries. 相似文献
6.
在传统聚光条件下的太阳能光伏发电系统中,由于太阳光中存在所有波段的光子,而其中只有一部分能够被太阳电池用来发电,其余的部分进入太阳电池之后非但不会被用于发电,反而会变成热量使太阳电池升温,从而使电池光电转换效率下降.本文设计了一种聚光且具有分频功能的太阳能电热联产系统,利用线聚焦菲涅尔透镜和光谱选择性透过涂层改善太阳电池表面的入射光环境,在聚光的同时将不利于光伏发电的太阳光波段反射并加以收集利用.分析结果表明,与相同条件下传统的只进行聚光的光伏系统相比,两级透射一反射聚光分频电热联产系统具有更高的太阳能利用效率. 相似文献
7.
Gd2(MoO4)3:Er3+ Nanophosphors for an Enhancement of Silicon Solar-Cell Near-Infrared Response 总被引:1,自引:0,他引:1
In an attempt to take full advantage of near-infrared part of the solar spectrum, Gd2(MoO4)3:Er3+ nanophosphors have been proposed as potential luminescent materials to enhance the response of the silicon solar-cell. Upon
excitation with low-energy near-infrared photons, intense upconverted emissions at 545, 665, 800, and 980 nm, for which energies
higher than the bandgap of silicon solar-cell, have been achieved with conversion efficiencies of 0.12%, 0.05%, 0.83%, and
1.35%, respectively. Development of nanophosphors for photovoltaic purposes could open up an approach in achieving high-efficiency
silicon-based solar-cell by means of the up-conversion of the sub-bandgap near-infrared part of the solar spectrum (E < 1.12 eV) to visible/near-infrared photons. 相似文献
8.
V. M. Andreev N. Yu. Davidyuk E. A. Ionova P. V. Pokrovskii V. D. Rumyantsev N. A. Sadchikov 《Technical Physics》2010,55(2):277-284
Two main issues governing the design of a solar concentrator module with triple-junction nano-heterostructure photovoltaic
converters (PVCs) are considered: the effective concentration of radiation using Fresnel lenses and effective heat removal
from PVCs. By theoretically and experimentally simulating these processes, the design parameters of module’ s elements are
determined. A test batch of full-size modules has been fabricated. Each module consists of a front panel of small-size Fresnel
lenses (a total of 144 lenses arranged as a 12 × 12 array) and the corresponding number of multilayer InGaP/GaAs/Ge PVCs.
The PVCs are mounted on heat-distributing plates and are also integrated into a panel. The efficiency of the concentrator
module with a 0.5 × 0.5-m entrance aperture measured under outdoor conditions is 24.3%, which is more than twice as high as
the efficiency of standard (concentrator-free) silicon modules. In smaller test modules, the efficiency corrected for the
PVC standard temperature (25° C) reaches 26.5%. 相似文献
9.
10.
《Current Applied Physics》2014,14(5):731-737
The output energy of photovoltaic (PV) modules under outdoor conditions is greatly influenced by the spectral irradiance distribution of the solar spectrum. To analyze this effect on PV modules, the spectral irradiance distribution, which is one-dimensional data, has to be represented by a zero-dimensional index. The average photon energy (APE) is an index for spectral irradiance distributions, which represents the average energy per photon in a spectrum. We have previously analyzed the uniqueness of the shape of the solar spectrum in the wavelength range of 350–1050 nm, and one corresponding value of APE showed a specific shape of spectral irradiance distribution. In this study, new indexes were calculated for a limited wavelength range of 350–750 nm and multiple bands of 450–500 nm and 800–850 nm of the solar spectrum for easy measurement and calculation. The result shows the uniqueness of new indexes to the shape of measured solar spectrum and the standard deviations were found to be quite small. This indicates that the new indexes are reasonable for representing the spectral irradiance distribution and its effect on PV performance. 相似文献
11.
A sensitive and selective method for the trace determination of 3, 3’, 4, 4’-tetrachlorobiphenyl (PCB77) by using bovine serum
albumin (BSA) as a fluorescence probe was introduced. Under optimum conditions, the enhanced fluorescence intensity was proportional
to the concentration of polychlorinated biphenyls in the range of 8.9 × 10−8–5.0 × 10−6 mol L−1 for PCB77, and 5.0 × 10−7–5.0 × 10−6 mol L−1 for 2, 2’, 5, 5’-tetrachlorbiphenyl (PCB52). The detection limits (S/N = 3) of PCB77 and PCB52 were 2.6 × 10−8 mol L−1 and 2.9 × 10−7 mol L−1, respectively. Furthermore, the fluorescence enhancement mechanism was discussed in detail. Results indicated that fluorescence
enhancement of the system originated from the formation of BSA-PCBs complexes. In addition, PCBs were mainly bound to the
tyrosine residues in BSA molecules. 相似文献
12.
The paper presents a part of research targeted at the modification of crystalline silicon solar cell production using screen-printing
technology. The proposed process is based on diffusion from POCl3 resulting in emitter with a sheet resistance on the level of 70 Ω/□ and then, shaped by high temperature passivation treatment.
The study was focused on a shallow emitter of high resistivity and on its influence on output electrical parameters of a solar
cell. Secondary ion mass spectrometry (SIMS) has been employed for appropriate distinguishing the total donor doped profile.
The solar cell parameters were characterized by current-voltage characteristics and spectral response (SR) methods. Some aspects
playing a role in suitable manufacturing process were discussed. The situation in a photovoltaic industry with emphasis on
silicon supply and current prices of solar cells, modules and photovoltaic (PV) systems are described. The economic and quantitative
estimation of the PV world market is shortly discussed. 相似文献
13.
Effect of plasticizers on electrical and photovoltaic properties of safranine-T-dye-based solid-state photo electrochemical
cell (PEC) is studied. Ethylene carbonate (EC) and propylene carbonate (PC) are used as plasticizers. Dark current–voltage
characteristic and different photovoltaic parameters such as open-circuit voltage, short-circuit current, and power conversion
efficiency are measured. To understand the effect of plasticizers on charge transport process, we analyze the dark current–voltage
characteristics to estimate the trap energy. From detail analysis of dark I–V, it has been observed that there is a crossover
voltage called transition voltage where the conduction mechanism changes. Above this voltage, the dark current is a space charge limited current (SCLC) in
the presence of exponentially distributed traps. Below transition voltage, current is ohmic for the cell without plasticizers
and dark current is an SCLC in presence of discrete traps for the cell with plasticizers. From our analysis, it is shown that
the transition voltage reduces due to the presence of plasticizers but the characteristic trap energy (ET) is not changed significantly. From photovoltaic measurements, it is observed that in presence of EC and PC power conversion
efficiency of the device increase from 7.319 × 10−4% to 14.64 × 10−4% under illumination with polychromatic light of 100 mW/cm2. It is expected that the power conversion efficiency depend on transition voltage. Due to the presence of plasticizers, the
barrier potentials of the devices reduce which results lowering of transition voltage. Lowering of it assists the migration
of charge carriers and as a result power conversion efficiency enhances. 相似文献
14.
Bruno B. Campos Manuel Algarra Joaquim C. G. Esteves da Silva 《Journal of fluorescence》2010,20(1):143-151
A fluorescent hybrid cadmium sulphide quantum dots (QDs) dendrimer nanocomposite (DAB-CdS) synthesised in water and stable
in aqueous solution is described. The dendrimer, DAB-G5 dendrimer (polypropylenimine tetrahexacontaamine) generation 5, a
diaminobutene core with 64 amine terminal primary groups. The maximum of the excitation and emission spectra, Stokes’ shift
and the emission full width of half maximum of this nanocomposite are, respectively: 351, 535, 204 and 212 nm. The fluorescence
time decay was complex and a four component decay time model originated a good fit (χ = 1.20) with the following lifetimes: τ
1 = 657 ps; τ
2 = 10.0 ns; τ
3 = 59.42 ns; and τ
4 = 265 ns. The fluorescence intensity of the nanocomposite is markedly quenched by the presence of nitromethane with a dynamic
Stern-Volmer constant of 25 M−1. The quenching profiles show that about 81% of the CdS QDs are located in the external layer of the dendrimer accessible
to the quencher. PARAFAC analysis of the excitation emission matrices (EEM) acquired as function of the nitromethane concentration
showed a trilinear data structure with only one linearly independent component describing the quenching which allows robust
estimation of the excitation and emission spectra and of the quenching profiles. This water soluble and fluorescent nanocomposite
shows a set of favourable properties to its use in sensor applications. 相似文献
15.
The dielectric constant and the electrical conductivity of the transparent glasses in the composition 3Na2O-7B2O3 (NBO) were investigated in the 100 Hz–10 MHz frequency range at various temperatures. The activation energy associated with
the electrical relaxation determined from the electric modulus spectra was found to be 0.76 ± 0.02 eV, close to that (0.74 ± 0.02 eV)
obtained from DC conductivity studies. The frequency-dependent electrical conductivity was analyzed using Jonscher’s power
law. Temperature-dependent behavior of the frequency exponent (n) suggested that the correlated-barrier hopping model was the most appropriate to rationalize the electrical transport phenomenon
in NBO glasses. 相似文献
16.
Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing 总被引:1,自引:0,他引:1
G. Wysocki R. Lewicki R.F. Curl F.K. Tittel L. Diehl F. Capasso M. Troccoli G. Hofler D. Bour S. Corzine R. Maulini M. Giovannini J. Faist 《Applied physics. B, Lasers and optics》2008,92(3):305-311
Recent progress in the development of room temperature, continuous wave, widely tunable, mode-hop-free mid-infrared external
cavity quantum cascade laser (EC-QCL) spectroscopic sources is reported. A single mode tuning range of 155 cm-1 (∼ 8% of the center wavelength) with a maximum power of 11.1 mW and 182 cm-1 (∼ 15% of the center wavelength) with a maximum power of 50 mW was obtained for 5.3 and 8.4 μm EC-QCLs respectively. This
technology is particularly suitable for high resolution spectroscopic applications, multi species trace-gas detection and
spectroscopic measurements of broadband absorbers. Several examples of spectroscopic measurements performed using EC-QCL based
spectrometers are demonstrated.
PACS 42.55.Px; 42.60.-v; 42.62.Fi; 07.07.Df 相似文献
17.
B. Khoshnevisan Z.S. Tabatabaean 《Applied Physics A: Materials Science & Processing》2008,92(2):371-374
We study the electronic dispersion for a graphene sheet and also a (5,5) single wall carbon nanotube (SWCNT) by using the
PWscf code from the ‘Quantum Espresso’ package. Two different types of pseudopotentials, ‘norm conserving’ and ‘ultra soft’,
have been employed and the results are more or less similar up to the Fermi level. By energy relaxation, it was found that,
if the inter-layer distance of graphite expands up to 4.5 times its in-layer (hexagonal) lattice constant, then each layer
can be considered as an individual graphene sheet and, in a bundle of (5,5) SWCNTs, the optimum separation between the tubes’
centers is about 19 a.u. and, if it expands to 22 a.u., then a single wall tube consideration can be made. The calculated
band structure and density of states (DOS) for the (5,5) SWCNT show that in the vicinity of the Fermi level there is no energy
gap (so that it is metallic) and there is a general agreement between them and zone-folding studies or other ab initio methods
in the literature. The effects of curvature on the band shifts and DOS have been considered, and they magnify the departure
from Mintmire and White’s universal prediction.
PACS 71.20.Tx; 71.15.Mb; 73.61.Wp 相似文献
18.
Uwe Rau Kurt Taretto Susanne Siebentritt 《Applied Physics A: Materials Science & Processing》2009,96(1):221-234
The paper reviews the current status of the research on grain boundaries in polycrystalline Cu(In, Ga)(S, Se)2 alloys used as absorber materials for thin-film solar cells. We discuss the different concepts that are available to explain
the relatively low electronic activity of grain boundaries in these materials. Numerical simulations that have been undergone
so far to model the polycrystalline solar cells are briefly summarized. In addition, we give an overview on the experiments
that have been conducted so far to elucidate the structural, defect-chemical, and electronic properties of grain boundaries
in Cu(In, Ga)(S, Se)2 thin-films. 相似文献
19.
The electrical properties and electromechanical responses of acrylic elastomers and styrene copolymers were investigated towards
electroactive applications such as artificial muscle and/or MEMS (micro-electro-mechanical systems) devices. The effect of
temperature, between 300 and 370 K, on electrical conductivity, dielectric constant, storage and loss moduli (G’ and G”),
storage modulus response (ΔG’2 kV/mm), and the storage modulus sensitivity (ΔG’2 kV/mm/G’0) of acrylic elastomers and styrene copolymers were investigated under applied electric field strengths varying from 0 to
2 kV/mm. The acrylic elastomers (AR70, AR71, and AR72) possess linearly positive storage modulus responses or sensitivities
with increasing temperature and dielectric constant. On the other hand, the styrene copolymers (SAR, SBS, and SIS) attain
the maximum storage modulus responses or sensitivities at the glass-transition temperature of the hard segments.
PACS 77.22.-d; 82.35.Lr; 83.60.Np; 83.80.Va; 91.60.Ki 相似文献
20.
Andrei V. Pakoulev Vladimir Burtman 《Applied Physics A: Materials Science & Processing》2010,98(4):717-734
This paper focuses on the intrinsic charge transport in self-assembled monolayers (SAMs) and on the nature of transport in
organic systems, in which surface and bulk properties are undistinguishable due to scale of consistent materials. Developed
SAM-OFETs and photovoltaic (SAM-PVC) devices are characterized independently to study a role of charge delocalization both
in electrical and optical manifold. The dynamics of charge transport are determined and used to clarify a transport mechanism.
Taken together, these SAM devices provide a unique tool to study the fundamentals of polaronic transport on organic surfaces
and to discuss the SAM-OFET and SAM PVC performance. Vapor phase molecular self-assembly of 1, 4, 5, 8-naphthalene-tetracarboxylic
diphenylimide (NTCDI) having a rich π-stacking charge delivery system is used to enhance the performance of SAM-OFET and SAM PVC devices. Charge mobility in SAM-OFET
could achieve values of more than 30 cm2 V−1 s−1. The dynamics of charge transport in NTCDI-derived SAM-OFETs were probed using time-resolved measurements in an NTCDI-derived
photovoltaic cell device. Time-resolved photovoltaic studies allow us to separate the charge annihilation kinetics in the
conductive NTCDI channel from the overall charge kinetic in a SAM-OFET device. It has been demonstrated that tuning of the
type of conductivity in NTCDI SAM-OFET devices is possible by changing Si substrate doping. In addition, the possibility of
measuring transport in highly ordered SAM structures shines light on the polaron charge transfer in organic materials. Our
study proposes that a cation-radical exchange (redox) mechanism is the major transport mechanism in SAM nanodevices. The role
and contribution of the transport through delocalized states of redox active surface molecular aggregates of NTCDI are exposed
and investigated in this report. 相似文献