Study on the Performance of Aluminum Thick Film Contacts for Silicon Solar Cells

2013 ◽  
Vol 833 ◽  
pp. 241-246
Author(s):  
Ming Fu ◽  
Hong Yong Li ◽  
Gong Lei Jin ◽  
Lin Fan ◽  
Dong Chen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Thick Film ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Silicon Solar Cells ◽  
Back Surface ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Photoelectric Properties

Aluminum rear contacts of silicon solar cells are made commonly by screen-printing aluminum paste and sintering process. Aluminum thick film contacts have a direct effect on photoelectric properties of solar cells, like open circuit voltage (Voc), short circuit current (Isc), conversion efficiency (η), etc. The principle of Al-back surface field (BSF) has been studied in this paper. With thermal gravimetric analysis and differential scanning calorimetry (TGA-DSC) method, the chemical reactions between aluminum thick film and silicon substrate during heat treatment have been investigated. The microstructure of aluminum thick film contacts were analysed by SEM. The electrical properties of Al-BSF are improved by adding a proper amount of nano silicon to the aluminum paste.

The Effect of Al-BSF on Seff and Rb in Industrialized Mono-Silicon Solar Cells

2012 ◽  
Vol 472-475 ◽  
pp. 1846-1850
Author(s):  
Shan Shan Dai ◽  
Gao Jie Zhang ◽  
Xiang Dong Luo ◽  
Jing Xiao Wang ◽  
Wen Jun Chen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Spectral Response ◽  
Short Circuit ◽  
Rear Surface ◽  
Surface Recombination ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Surface Recombination Velocity ◽  
Silicon Solar Cells ◽  
Back Surface

In this work, the effect of aluminum back surface field formed by screen printed various amount of Al paste on the effective rear surface recombination velocity (Seff) and the internal rear reflectance coeffeicient (Rb) of commercial mono-silicon solar cells was investigated. We demonstrated the effect of Seffand Rbon the performance of Al-BSF solar cells by simulating them with PC1D. The simulated results showed that the lower Seffcould get higher open circuit voltage (Voc), at the same time, the larger Rbcould get higher short-circuit current (Isc). Experimentally, we investigated the Seffand Rbthrough depositing Al paste with various amount (3.7, 5, 6, and 8 mg/cm2) for fabricating Al-BSF mono-silicon solar cells. Four group cells were characterized by light I-V, spectral response, hemispherical reflectance and scanning electron microscope (SEM) measurements. It was found that, a minimum Seffof 350 cm/s was gotten from the cells with Al paste of 8 mg/cm2, which was extracted by matching quantum efficiency (QE) from 800 nm to 1200 nm with PC1D, and a maximum Rbof 53.5% was obtained from Al paste of 5 mg/cm2by calculating at 1105 nm with PC1D. When the amount of Al paste was higher than 5mg/cm2, there were less Seffand lower Rb. On the other hand, when Al amount was 3.7mg/cm2, it was too little to form a closed BSF. Based on the SEM graphs and simulations with PC1D, a simple explaination was proposed for the experimental results.

The influence of emitter resistance on the electrical parameters of mono- and multicrystalline silicon solar cells

2019 ◽  
Vol 36 (3) ◽  
pp. 90-94
Author(s):  
Barbara Swatowska ◽  
Piotr Panek ◽  
Dagmara Michoń ◽  
Aleksandra Drygała
Keyword(s):  
Solar Cells ◽  
Contact Resistance ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Multicrystalline Silicon ◽  
Silicon Solar Cells ◽  
Electrical Parameters ◽  
Content Type ◽  
Diffusion Parameters

Purpose The purpose of this study was the comparison and analysis of the electrical parameters of two kinds of silicon solar cells (mono- and multicrystalline) of different emitter resistance. Design/methodology/approach By controlling of diffusion parameters, silicon mono- (Cz-Si) and multicrystalline (mc-Si) solar cells with different emitter resistance values were produced – 22 and 48 Ω/□. On the basis of current-voltage measurements of cells and contact resistance mapping, the properties of final solar cells based on two different materials were compared. Additionally, the influence of temperature on PV cells efficiency and open circuit voltage (Uoc) were investigated. The PC1D simulation was useful to determine spectral dependence of external quantum efficiency of solar cells with different emitter resistance. The silicon solar cells of 25 cm2 area and 240 µm thickness were investigated. Findings Considering the all stages of cell technology, the best structure is silicon solar cell with sheet resistance (Rsheet) of 45-48 Ω/□. Producing of an emitter with this resistance allowed to obtain cells with a fill factor between 0.725 and 0.758, Uoc between 585 and 612 mV, short circuit current (Isc) between 724 and 820 mA. Originality/value Measurements and analysis confirmed that mono- and multicrystalline silicon solar cells with 48 Ω/□ emitter resistance have better parameters than cells with Rsheet of 22 Ω/□. The contact resistance is the highest for mc-Si with Rsheet of 48 Ω/□ and reaches the value 3.8 Ωcm.

Simulation of Symmetrically Doped Silicon Nanowire Solar Cells

2011 ◽  
Vol 1322 ◽  
Author(s):  
Felix Voigt ◽  
Thomas Stelzner ◽  
Silke H. Christiansen
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Silicon Nanowire ◽  
Short Circuit Current ◽  
Cylindrical Symmetry ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Back Surface ◽  
Cell Efficiency ◽  
P Type

ABSTRACTSilicon nanowire solar cells were simulated using the Silvaco TCAD software kit. For optimization of speed the simulations were performed in cylinder coordinates with cylindrical symmetry. Symmetric doping was assumed with a dopant density of 1018 cm-3 in the p-type core and inside the n-type shell. In the implementation a cathode contact was wrapped around the semiconductor nanorod and an anode was assumed at the bottom of the rod. Optimization of cell efficiency was performed with regard to the rod radius and the rod length. In both optimization processes clear maxima in efficiency were visible, resulting in an optimal radius of 66 nm with the pn junction at 43.5 nm and an optimal rod length of about 48 μm. The maximum of efficiency with respect to the rod radius is due to a decrease of short-circuit current density (Jsc) and an increase of open-circuit voltage (Uoc) with radius, while the maximum with respect to the rod length is explained by the combination of an increase of Jsc and a decrease of Uoc. Fill factors stay rather constant at values between 0.6 and 0.8. Further, the influence of a back surface field (BSF) layer was surveyed in simulations. Positioning the BSF next to the cathode contact considerably improved cell efficiency. In addition, simulations with a cathode contact on top of the nanowire structure were undertaken. No severe deterioration of cell performance with increasing radius was observed so far in this configuration. Hence, nanorods with much larger radii can be used for solar cells using this contact scheme. In comparison to simulations with wrapped cathode contacts, Jsc and Uoc and therefore efficiency is considerably improved.

High efficiency p+-n-n+ back-surface field silicon solar cells with very large short-circuit current densities

Solar Cells ◽  
1982 ◽  
Vol 7 (3) ◽  
pp. 331-336 ◽  
Author(s):  
J. Nijs ◽  
J. Van Meerbergen ◽  
F. D'Hoore ◽  
R. Mertens ◽  
R. Van Overstraeten
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Silicon Solar Cells ◽  
Back Surface ◽  
Back Surface Field ◽  
Surface Field ◽  
Current Densities

N-Type Hydrogenated Microcrystalline Silicon Oxide Films and Their Applications in Micromorph Silicon Solar Cells

2011 ◽  
Vol 1321 ◽  
Author(s):  
Amornrat Limmanee ◽  
Songkiate Kittisontirak ◽  
Channarong Piromjit ◽  
Jaran Sritharathikhun ◽  
Kobsak Sriprapha
Keyword(s):  
Solar Cells ◽  
Silicon Oxide ◽  
Volume Fraction ◽  
Short Circuit ◽  
Oxide Films ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Silicon Solar Cells ◽  
Microcrystalline Silicon ◽  
Shunt Resistance

ABSTRACTWe have prepared n-type hydrogenated microcrystalline silicon oxide films (n μc-SiO:H) and investigated their structural, electrical and optical properties. Raman spectra shows that, amorphous phase of the n μc-SiO:H films tends to increase when the CO2/SiH4 ratio increases from 0 to 0.28 resulting in a reduction of the crystalline volume fraction (Xc) from 70 to 12%. Optical bandgap (E04) becomes gradually wider while dark conductivity and refractive index (n) continuously drop with increasing CO2/SiH4 ratio. The n μc-SiO:H films have been practically applied as a n layer in top cell of a-SiO:H/μc-Si:H micromorph silicon solar cells. We found that, open circuit voltage (Voc) and fill factor (FF) of the cells gradually increased, while short circuit current density (Jsc) remained almost the same value with increasing CO2/SiH4 ratio for n top layer deposition up to 0.23. The highest initial cell efficiency of 10.7% is achieved at the CO2/SiH4 ratio of 0.23. The enhancement of the Voc is supposed to be due to a reduction of reverse bias at sub cell connection (n top/p bottom interface). An increase of shunt resistance (Rsh) which is caused by a better tunnel recombination junction contributes to the improvement in the FF. Quantum efficiency (QE) results indicate no difference between the cells using n top μc-SiO:H and the cells with n top μc-Si:H layers. These results reveal that, the n μc-SiO:H films in this study do not work as an intermediate reflector to enhance light scattering inside the solar cells, but mainly play a key role to allow ohmic and low resistive electrical connection between the two adjacent cells in the micromorph silicon solar cells.

A Carrier Lifetime Model for the Optical Degradation of Amorphous Silicon Solar Cells

1985 ◽  
Vol 49 ◽  
Author(s):  
Z E. Smith ◽  
S. Wagner
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Carrier Lifetime ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Silicon Solar Cells ◽  
Carrier Lifetimes ◽  
Bond Density ◽  
Degradation Data

AbstractThe light-induced performance degradation of amorphous silicon solar cells is described well by a model in which the carrier lifetimes are determined by the dangling bond density. The kinetics of the defect generation follow the model in which band-to-band recombination provides the energy for the creation of dangling bonds, which in turn introduce gap states that reduce carrier lifetime. Degradation will be slower in solar cells operating at lower excess carrier concentrations. This is documented with a comparison of degradation data for cells of different i-layer thickness, cells operating at open circuit vs. load, and for single vs. cascade cells. The model also correctly predicts the relation between short circuit current and fill factor degradation. At sufficiently long times, the efficiency will decrease at approximately the same rate for all cell structures and dimensions, with an offset in time between different device types which can be calculated.

The Effect of Diatomite on the Photoelectric Properties of TiO2 Dye Sensitized Solar Cells

2013 ◽  
Vol 448-453 ◽  
pp. 1452-1456
Author(s):  
Jiang Biao Feng ◽  
Ling Jun Hua ◽  
Feng Jun Shan ◽  
Zhi Gang Yan ◽  
Guo Chao Qi
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Composite Films ◽  
Dye Sensitized Solar Cells ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Dye Sensitized ◽  
Conductive Glass ◽  
Photoelectric Properties ◽  
Sensitized Solar Cells

Diatomite/TiO2 composite films were prepared with diatomite and P25 TiO2 nanoparticles on conductive glass substrates. The surface morphology and phase composition of the film were characterized with scanning electron microscopy (SEM) and X ray diffraction (XRD). It is concluded that diatomite doped into the film will form granular cores. Dye sensitized solar cells (DSSC) were fabricated with the diatomite/TiO2 composite film as anode, and the photoelectric properties of the cells were tested. Results show that the doping of diatomite can significantly increase the open circuit voltage and short circuit current of DSSC. Optimized photoelectric properties can be acquired as 1.3 percent diatomite doped in TiO2 film.

scholarly journals Cheap Sensor Made of Multicrystalline Silicon for Insolation and Temperature Measurements

2016 ◽  
Vol 23 (4) ◽  
pp. 583-591 ◽  
Author(s):  
Tadeusz Rodziewicz ◽  
Janusz Teneta ◽  
Aleksander Zaremba ◽  
Maria Wacławek
Keyword(s):  
Solar Cells ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
The Other ◽  
Silicon Solar Cells ◽  
Temperature Calculation ◽  
Direct Indication ◽  
Indirect Indication

Abstract In the paper some results on measurement of insolation and „real” cell’s temperature carried out with use of standard silicon solar cells are presented. Two identical cells are applied in such a sensor. Short circuit current of one cell is a direct indication of insolation value and open circuit voltage of the other cell is indirect indication of actual sensor’s temperature but in this case more complex formula must be used for temperature calculation.

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