scholarly journals Matching of Silicon Thin-Film Tandem Solar Cells for Maximum Power Output

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
C. Ulbrich ◽  
C. Zahren ◽  
A. Gerber ◽  
B. Blank ◽  
T. Merdzhanova ◽  
...  
Keyword(s):  
Solar Cells ◽  
Output Power ◽  
Power Output ◽  
Short Circuit ◽  
Matching Condition ◽  
Measurement Procedure ◽  
Maximum Power ◽  
Silicon Thin Film ◽  
Tandem Solar Cells ◽  
Maximum Power Output

We present a meaningful characterization method for tandem solar cells. The experimental method allows for optimizing the output power instead of the current. Furthermore, it enables the extraction of the approximate AM1.5g efficiency when working with noncalibrated spectra. Current matching of tandem solar cells under short-circuit condition maximizes the output current but is disadvantageous for the overall fill factor and as a consequence does not imply an optimization of the output power of the device. We apply the matching condition to the maximum power output; that is, a stack of solar cells is power matched if the power output of each subcell is maximal at equal subcell currents. The new measurement procedure uses additional light-emitting diodes as bias light in theJVcharacterization of tandem solar cells. Using a characterized reference tandem solar cell, such as a hydrogenated amorphous/microcrystalline silicon tandem, it is possible to extract the AM1.5g efficiency from tandems of the same technology also under noncalibrated spectra.

Performance of Silicon Solar Cells at High Levels of Solar Radiation

1962 ◽  
Vol 84 (1) ◽  
pp. 33-38 ◽  
Author(s):  
C. Pfeiffer ◽  
P. Schoffer ◽  
B. G. Spars ◽  
J. A. Duffie
Keyword(s):  
Solar Cells ◽  
Solar Radiation ◽  
Power Output ◽  
Maximum Power ◽  
Silicon Solar Cells ◽  
Maximum Power Output ◽  
Measuring Devices ◽  
Current Voltage ◽  
Current Voltage Characteristics

Current-voltage characteristics of silicon solar cells cooled by conduction or convection at radiation levels up to 60 langleys per minute are reported for several cell temperatures. Maximum power output noted was approximately 65 milliwatts per square centimeter. The use of cells as flux measuring devices is noted.

Analytical Study and Experimental Validation of Copper II Sulfate and Potassium Ferri/Ferrocyanide Thermocells Using Onsager Flux Equations

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Alex M. Bates ◽  
Ben Zickel ◽  
Steffen Krebs ◽  
Santanu Mukherjee ◽  
Nicholas D. Schuppert ◽  
...  
Keyword(s):  
Power Output ◽  
Analytical Study ◽  
Electrode Materials ◽  
Experimental Testing ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrical Energy ◽  
Maximum Power ◽  
Electrode Spacing ◽  
Maximum Power Output

Thermocells convert heat energy directly into electrical energy through charge-transfer reactions at the electrode–electrolyte interface. To perform an analytical study on the behavior of thermocells, the Onsager flux relationship was applied to thermocells, which used aqueous copper II sulfate and aqueous potassium ferri/ferrocyanide as the electrolyte. The transport coefficient matrices were calculated for each electrolyte and applied to several simulations, which were subsequently validated through experimental testing and comparison to previous literature results. The simulation is shown to correctly predict the short circuit current, maximum power output, and power conversion efficiency. Validation demonstrates that the simulation model developed, using the Onsager flux equations, works for thermocells with different electrode materials (platinum, copper, charcoal, acetylene black, and carbon nanotube), electrode spacing, and temperature differentials. The power dependence of the thermocell on concentration and electrode spacing, with respect to the Seebeck coefficient, maximum power output, and relative efficiency, is also shown.

scholarly journals Comparing the performance of Organic-inorganic hybrid tandem multijunction solar cells of different organic bulk thicknesses

2015 ◽  
Vol 37 ◽  
pp. 49
Author(s):  
Abdolnabi Kosarian ◽  
Mehrdad Kankanan ◽  
Mohamad Ali Khalafi
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Maximum Power ◽  
Maximum Power Point ◽  
Tandem Solar Cells ◽  
Multijunction Solar Cells ◽  
Power Point

In this study, J-V curves of a-Si:H/PCPDTBT:PC70BM hybrid tandem solar cells were simulated using a modified drift-diffusion model, and the influence of the thickness of the organic blend layer was investigated. The results of the simulations were compared with experimental data from literature.It is shown that as the thickness of the blend layer increases, the fill factor and the voltage corresponding to maximum power point decrease whereas the maximum power point and the short circuit current density of solar cell increase up to thicknesses of 60 nm and 138 nm respectively. Finally, the modified organic solar cell was used as second sub-cell and the power conversion efficiency increased from 1.90% to 2.1% in simulation.

scholarly journals Optimization of Recombination Layer in the Tunnel Junction of Amorphous Silicon Thin-Film Tandem Solar Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Yang-Shin Lin ◽  
Shui-Yang Lien ◽  
Chao-Chun Wang ◽  
Chia-Hsun Hsu ◽  
Chih-Hsiang Yang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
High Efficiency ◽  
Short Circuit ◽  
Open Circuit ◽  
Maximum Efficiency ◽  
Manufacturing Cost ◽  
Silicon Thin Film ◽  
Tandem Solar Cells ◽  
Tandem Cell

The amorphous silicon/amorphous silicon (a-Si/a-Si) tandem solar cells have attracted much attention in recent years, due to the high efficiency and low manufacturing cost compared to the single-junction a-Si solar cells. In this paper, the tandem cells are fabricated by high-frequency plasma-enhanced chemical vapor deposition (HF-PECVD) at 27.1 MHz. The effects of the recombination layer and the i-layer thickness matching on the cell performance have been investigated. The results show that the tandem cell with a p+recombination layer and i2/i1thickness ratio of 6 exhibits a maximum efficiency of 9.0% with the open-circuit voltage (Voc) of 1.59 V, short-circuit current density (Jsc) of 7.96 mA/cm2, and a fill factor (FF) of 0.70. After light-soaking test, our a-Si/a-Si tandem cell with p+recombination layer shows the excellent stability and the stabilized efficiency of 8.7%.

Oxidation of combined ingestion of glucose and fructose during exercise

2004 ◽  
Vol 96 (4) ◽  
pp. 1277-1284 ◽  
Author(s):  
Roy L. P. G. Jentjens ◽  
Luke Moseley ◽  
Rosemary H. Waring ◽  
Leslie K. Harding ◽  
Asker E. Jeukendrup
Keyword(s):  
Power Output ◽  
Statistical Significance ◽  
Random Order ◽  
Carbohydrate Oxidation ◽  
Maximum Power ◽  
The Other ◽  
Cycling Exercise ◽  
Oxidation Rates ◽  
Maximum Power Output ◽  
Exercise Period

The purpose of the present study was to examine whether combined ingestion of a large amount of fructose and glucose during cycling exercise would lead to exogenous carbohydrate oxidation rates >1 g/min. Eight trained cyclists (maximal O2consumption: 62 ± 3 ml·kg-1·min-1) performed four exercise trials in random order. Each trial consisted of 120 min of cycling at 50% maximum power output (63 ± 2% maximal O2consumption), while subjects received a solution providing either 1.2 g/min of glucose (Med-Glu), 1.8 g/min of glucose (High-Glu), 0.6 g/min of fructose + 1.2 g/min of glucose (Fruc+Glu), or water. The ingested fructose was labeled with [U-13C]fructose, and the ingested glucose was labeled with [U-14C]glucose. Peak exogenous carbohydrate oxidation rates were ∼55% higher ( P < 0.001) in Fruc+Glu (1.26 ± 0.07 g/min) compared with Med-Glu and High-Glu (0.80 ± 0.04 and 0.83 ± 0.05 g/min, respectively). Furthermore, the average exogenous carbohydrate oxidation rates over the 60- to 120-min exercise period were higher ( P < 0.001) in Fruc+Glu compared with Med-Glu and High-Glu (1.16 ± 0.06, 0.75 ± 0.04, and 0.75 ± 0.04 g/min, respectively). There was a trend toward a lower endogenous carbohydrate oxidation in Fruc+Glu compared with the other two carbohydrate trials, but this failed to reach statistical significance ( P = 0.075). The present results demonstrate that, when fructose and glucose are ingested simultaneously at high rates during cycling exercise, exogenous carbohydrate oxidation rates can reach peak values of ∼1.3 g/min.

scholarly journals Scaling of Power Output in Fast Muscle Fibres of the Atlantic Cod During Cyclical Contractions

1992 ◽  
Vol 170 (1) ◽  
pp. 143-154 ◽  
Author(s):  
M. ELIZABETH ANDERSON ◽  
IAN A. JOHNSTON
Keyword(s):  
Steady State ◽  
Power Output ◽  
Standard Length ◽  
Atlantic Cod ◽  
Maximum Power ◽  
Fast Muscle ◽  
Muscle Fibres ◽  
Cycle Frequency ◽  
Maximum Power Output ◽  
Length Changes

Fast muscle fibres were isolated from abdominal myotomes of Atlantic cod (Gadus morhua L.) ranging in size from 10 to 63 cm standard length (Ls). Muscle fibres were subjected to sinusoidal length changes about their resting length (Lf) and stimulated at a selected phase of the strain cycle. The work performed in each oscillatory cycle was calculated from plots of force against muscle length, the area of the resulting loop being net work. Strain and the number and timing of stimuli were adjusted to maximise positive work per cycle over a range of cycle frequencies at 8°C. Force, and hence power output, declined with increasing cycles of oscillation until reaching a steady state around the ninth cycle. The strain required for maximum power output (Wmax) was ±7-11% of Lf in fish shorter than 18 cm standard length, but decreased to ±5 % of Lf in larger fish. The cycle frequency required for Wmax also declined with increasing fish length, scaling to Ls−0.51 under steady-state conditions (cycles 9–12). At the optimum cycle frequency and strain the maximum contraction velocity scaled to Ls−0.79. The maximum stress (Pmax) produced within a cycle was highest in the second cycle, ranging from 51.3 kPa in 10 cm fish to 81.8 kPa in 60 cm fish (Pmax=28.2Ls0.25). Under steady-state conditions the maximum power output per kilogram wet muscle mass was found to range from 27.5 W in a 10 cm Ls cod to 16.4 W in a 60 cm Ls cod, scaling with Ls−0.29 and body mass (Mb)−0.10 Note: To whom reprint requests should be sent

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