IMPROVING n+pp+ SINGLE CRYSTALLINE SILICON SOLAR CELLS BY LONG HIGH TEMPERATURE Al ANNEALING

2001 ◽  
Vol 15 (17n19) ◽  
pp. 601-604 ◽  
Author(s):  
Guillermo Santana ◽  
Arturo Morales-Acevedo
Keyword(s):  
Solar Cells ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Solar Grade Silicon ◽  
Minority Carrier Diffusion Length ◽  
Crystalline Silicon Solar Cells ◽  
High Annealing ◽  
Metallic Impurities

In this work, we show that solar cells made on solar grade silicon can be improved by annealing them at high temperatures (800° C) after the aluminum at the back is evaporated. This improvement is larger for longer annealing times. Both the short circuit current (Isc) and the open circuit voltage (Voc) increase due to an increase of the base minority carrier diffusion length and a reduction of dark current, respectively. This effect may be due to "gettering" of metallic impurities and precipitates at the bulk and junction regions of the cells. For this high annealing temperature we observed that the increase of Jsc tends to saturate after 60 minutes, while Voc continues increasing for annealing times above 150 minutes.

scholarly journals Effect of the Phosphorus Gettering on Si Heterojunction Solar Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hyomin Park ◽  
Sung Ju Tark ◽  
Chan Seok Kim ◽  
Sungeun Park ◽  
Young Do Kim ◽  
...  
Keyword(s):  
Solar Cells ◽  
Current Density ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Solar Simulator ◽  
Heterojunction Solar Cells ◽  
Crystalline Silicon Solar Cells

To improve the efficiency of crystalline silicon solar cells, should be collected the excess carrier as much as possible. Therefore, minimizing the recombination both at the bulk and surface regions is important. Impurities make recombination sites and they are the major reason for recombination. Phosphorus (P) gettering was introduced to reduce metal impurities in the bulk region of Si wafers and then to improve the efficiency of Si heterojunction solar cells fabricated on the wafers. Resistivity of wafers was measured by a four-point probe method. Fill factor of solar cells was measured by a solar simulator. Saturation current and ideality factor were calculated from a dark current density-voltage graph. External quantum efficiency was analyzed to assess the effect of P gettering on the performance of solar cells. Minority bulk lifetime measured by microwave photoconductance decay increases from 368.3 to 660.8 μs. Open-circuit voltage and short-circuit current density increase from 577 to 598 mV and 27.8 to 29.8 mA/cm2, respectively. The efficiency of solar cells increases from 11.9 to 13.4%. P gettering will be feasible to improve the efficiency of Si heterojunction solar cells fabricated on P-doped Si wafers.

scholarly journals Degradation effects of the output electrical characteristics of Si solar cells as a result of ionizing radiation under low light conditions

2015 ◽  
Vol 30 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Nebojsa Stojanovic ◽  
Biljana Simic ◽  
Koviljka Stankovic ◽  
Djordje Lazarevic
Keyword(s):  
Solar Cells ◽  
Gamma Radiation ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Low Light ◽  
Crystalline Silicon Solar Cells ◽  
Current Maximum ◽  
Power Point

This paper presents results of radiation resistance of different types of commercially available single- and poly-crystalline silicon solar cells. Sample cells were subjected to gamma radiation from gamma radiation source 60Co. Characteristic parameters of solar cells were extracted from obtained I-V curves: open circuit voltage, short circuit current, maximum power point voltage and current, efficiency, fill factor, and series resistance. Obtained results show the level of parameters' degradation with purpose of increasing solar cells applications in radiation environments.

Measured and Simulated Temperature Dependence of A-Si:H Solar Cell Parameters

1996 ◽  
Vol 426 ◽  
Author(s):  
H. Stiebig ◽  
Th. Eickhoff ◽  
J. Zimmer ◽  
C. Beneking ◽  
H. Wagner
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Temperature Dependence ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Cell Parameters ◽  
Crystalline Silicon Solar Cells ◽  
Device Modelling

AbstractIn contrast to the successful application of analytic equations to the current-voltage behaviour of crystalline silicon solar cells in the dark and under AM1.5 illumination, the description of a-Si:H solar cells parameters requires device modelling concepts taking the full set of semiconductor equations into account. This in particular holds for the explanation of the temperature dependence (225–400K) of experimentally determined a-Si:H p-i-n solar cell parameters. Device modelling calculations show that the observed decrease of the short circuit current at AM 1.5 with lower T is much more effected by the additional charge trapped in the tail states and recharging of defect states than by the broadening of the gap. The induced electric field distortion blocks the extraction of photo generated holes. The open circuit voltage Voc increases with lower T which is caused by the same trapping effect.

Measured and Simulated Temperature Dependence of A-Si:H Solar Cell Parameters

1996 ◽  
Vol 420 ◽  
Author(s):  
H. Stiebig ◽  
Th. Eickhoff ◽  
J. Zimmer ◽  
C. Beneking ◽  
H. Wagner
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Temperature Dependence ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Cell Parameters ◽  
Crystalline Silicon Solar Cells ◽  
Device Modelling

AbstractIn contrast to the successful application of analytic equations to the current-voltage behaviour of crystalline silicon solar cells in the dark and under AM 1.5 illumination, the description of a-Si:H solar cells parameters requires device modelling concepts taking the full set of semiconductor equations into account. This in particular holds for the explanation of the temperature dependence (225-400K) of experimentally determined a-Si:H p-i-n solar cell parameters. Device modelling calculations show that the observed decrease of the short circuit current at AM 1.5 with lower T is much more effected by the additional charge trapped in the tail states and recharging of defect states than by the broadening of the gap. The induced electric field distortion blocks the extraction of photo generated holes. The open circuit voltage Voc increases with lower T which is caused by the same trapping effect.

scholarly journals Analytical Study of the Electrical Output Characteristics of c-Si Solar Cells by Cut and Shading Phenomena

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3397 ◽  
Author(s):  
Jong Lim ◽  
Woo Shin ◽  
Hyemi Hwang ◽  
Young-Chul Ju ◽  
Suk Ko ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Incident Light ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Si Solar Cell ◽  
Si Solar Cells ◽  
Electrical Output

Cut solar cells have received considerable attention recently as they can reduce electrical output degradation when the c-Si solar cells (crystalline-silicon solar cells) are shaded. Cut c-Si solar cells have a lower short-circuit current than normal solar cells and the decrease in short-circuit currents is similar to the shading effect of c-Si solar cells. However, the results of this study’s experiment show that the shadow effect of a c-Si solar cell reduces the V o c (open circuit voltage) in the c-Si solar cell but the V o c does not change when the c-Si solar cell is cut because the amount of incident light does not change. In this paper, the limitations of the electrical power analysis of the cut solar cells were identified when only photo current was considered and the analysis of the electric output of the cut c-Si solar cells was interpreted with a method different from that used in previous analyses. Electrical output was measured when the shaded and cut rates of c-Si solar cells were increased from 0% to 25, 50 and 75%, and a new theoretical model was compared with the experimental results using MATLAB.

scholarly journals Improvement of short circuit current of mono crystalline silicon solar cells

2013 ◽  
Vol 16 (1) ◽  
pp. 48-56
Author(s):  
Vu Ngoc Hoang ◽  
Linh Ngoc Tran ◽  
Lan Truong ◽  
Khoa Thanh Nhat Phan ◽  
Chien Mau Dang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Indium Tin Oxide ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Front Surface ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Crystalline Silicon Solar Cell ◽  
Antireflection Coatings

In this report we present series of experiments during which the short circuit current of mono crystalline silicon solar cell was improved step by step so as a consequence the efficiency was increased. At first, the front contact of solar cell was optimized to reduce the shadow loss and the series resistance. Then surface treatments were prepared by TMAH solution to reduce the total light reflectance and to improve the light trapping effect. Finally, antireflection coatings were deposited to passivate the front surface either by silicon nitride thin layer or to increase the collection probability by indium tin oxide layer, and to reduce the reflectance of light. As a result, solar cells of about 13% have been obtained, with the average open circuit voltage Voc about 527mV, with the fill factor about 68% and the short circuit current about 7.92 mA/cm2 under the irradiation density of 21 mW/cm2.

Shape-Controllable Surface Texturization for Crystalline Silicon Solar Cells

2008 ◽  
Vol 1101 ◽  
Author(s):  
Jong-San Im ◽  
Jin-Wan Jeon ◽  
Koeng Su Lim
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Inductively Coupled Plasma ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Crystalline Silicon Solar Cells ◽  
Inductively Coupled ◽  
Polymer Dispersed Liquid Crystal ◽  
Polymer Dispersed

AbstractThis paper describes a new method to make surface textures for photovoltaic application. Using this method, we can make textures having various shapes. The first step is to make photo-resist (PR) molds using the polymer dispersed liquid crystal (PDLC) film. The second step is to transfer the PR molds to silicon by inductively coupled plasma etching process. The final step is a solar cell fabrication process. The structure of the solar cell is simple Al Grid/c-Si/Al back contact. The solar cells show the increase of the short circuit current (Jsc) comparing to the planar cells. By this texturing method, we can get solar cells having various textures which we want to make.

Photovoltaic Characteristics of Ultra-Thin Single Crystalline Silicon Solar Cells

2016 ◽  
Vol 25 (01n02) ◽  
pp. 1640008
Author(s):  
R. Miyazawa ◽  
H. Wakabayashi ◽  
K. Tsutsui ◽  
H. Iwai ◽  
K. Kakushima
Keyword(s):  
Solar Cells ◽  
Crystalline Silicon ◽  
Spectral Response ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Response Measurement ◽  
Single Crystalline ◽  
Si Solar Cells ◽  
Photovoltaic Characteristics

Photovoltaic characteristics of ultra-thin single crystalline Si solar cells with thicknesses ranging from 7.6 to 3.3 nm are presented. While the short-circuit current (ISC) AM1.5 illumination has shown a linear relationship with the volume of the Si layer, a gradual increase in the open-circuit voltage (VOC) with thinner Si layer has been confirmed, implying the bandgap enlargement of the Si layer due to quantum confinement. Spectral response measurement has revealed an increased optical bandgap of 1.3 eV for 3.3-nm-thick Si solar cells, which is wider than that of 7.6-nm-thick Si ones. Although some process related issues have become clear during the fabrication of solar cells, they can be utilized as top cells for tandem configurations, exceeding the limit of the bulk Si solar cells.

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