scholarly journals Advantages of N-Type Hydrogenated Microcrystalline Silicon Oxide Films for Micromorph Silicon Solar Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Amornrat Limmanee ◽  
Songkiate Kittisontirak ◽  
Sorapong Inthisang ◽  
Taweewat Krajangsang ◽  
Jaran Sritharathikhun ◽  
...  
Keyword(s):  
Solar Cells ◽  
Silicon Oxide ◽  
Oxide Films ◽  
Open Circuit ◽  
Silicon Solar Cells ◽  
Microcrystalline Silicon ◽  
Cell Efficiency ◽  
Bottom Interface ◽  
Hydrogenated Amorphous ◽  
Recombination Junction

We report on the development and application of n-type hydrogenated microcrystalline silicon oxide films (nμc-SiO:H) in hydrogenated amorphous silicon oxide/hydrogenated microcrystalline silicon (a-SiO:H/μc-Si:H) micromorph solar cells. The nμc-SiO:H films with high optical bandgap and low refractive index could be obtained when a ratio of carbon dioxide (CO2) to silane (SiH4) flow rate was raised; however, a trade-off against electrical property was observed. We applied the nμc-SiO:H films in the top a-SiO:H cell and investigated the changes in cell performance with respect to the electrical and optical properties of the films. It was found that all photovoltaic parameters of the micromorph silicon solar cells using the n topμc-SiO:H layer enhanced with increasing the CO2/SiH4ratio up to 0.23, where the highest initial cell efficiency of 10.7% was achieved. The enhancement of the open circuit voltage (Voc) was likely to be due to a reduction of reverse bias at subcell connection—n top/p bottom interface—and a better tunnel recombination junction contributed to the improvement in the fill factor (FF). Furthermore, the quantum efficiency (QE) results also have demonstrated intermediate-reflector function of the nμc-SiO:H films.

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.

Microcrystalline silicon solar cells with passivated interfaces for high open-circuit voltage

2015 ◽  
Vol 212 (4) ◽  
pp. 840-845 ◽  
Author(s):  
Simon Hänni ◽  
Mathieu Boccard ◽  
Grégory Bugnon ◽  
Matthieu Despeisse ◽  
Jan-Willem Schüttauf ◽  
...  
Keyword(s):  
Solar Cells ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Silicon Solar Cells ◽  
Microcrystalline Silicon

scholarly journals Mixed phase silicon oxide layers for thin-film silicon solar cells

2011 ◽  
Vol 1321 ◽  
Author(s):  
Peter Cuony ◽  
Duncan T.L. Alexander ◽  
Linus Löfgren ◽  
Michael Krumrey ◽  
Michael Marending ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Silicon Oxide ◽  
Nanocrystalline Silicon ◽  
Silicon Solar Cells ◽  
Microstructural Properties ◽  
Microcrystalline Silicon ◽  
Thin Film Silicon ◽  
Transmission Electron ◽  
Doped Silicon

ABSTRACTLower absorption, lower refractive index and tunable resistance are three advantages of doped silicon oxide containing nanocrystalline silicon grains (nc-SiOx) compared to doped microcrystalline silicon, for the use as p- and n-type layers in thin-film silicon solar cells. In this study we show how optical, electrical and microstructural properties of nc-SiOx layers depend on precursor gas ratios and we propose a growth model to explain the phase separation in such films into Si-rich and O-rich regions as visualized by energy-filtered transmission electron microscopy.

Development of a-SiOx:H/a-Si1-xGex:H Tandem Solar Cell for Triple-Junction Solar Cell Applications

2012 ◽  
Vol 1426 ◽  
pp. 125-130
Author(s):  
Y.W. Tseng ◽  
Y.H. Lin ◽  
H.J. Hsu ◽  
C.H. Hsu ◽  
C.C. Tsai
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Silicon Oxide ◽  
Defect Density ◽  
Tandem Solar Cell ◽  
Tandem Solar Cells ◽  
Single Junction ◽  
Cell Efficiency ◽  
Photo Response ◽  
Hydrogenated Amorphous

ABSTRACTIn this work, the development of hydrogenated amorphous silicon oxide (a-SiOx:H) absorber, a-SiOx:H single-junction solar cells and a-SiOx:H/a-Si1-xGex:H tandem solar cells were presented. The oxygen content of the a-SiOx:H materials controlled by changing CO2-to-SiH4 flow ratio had significant influence on its opto-electrical property. As CO2/SiH4 increased from 0 to 2, the bandgap increased from 1.75 to 2.13 eV while the photo-conductivity decreased from 8.25×10-6 to 1.02×10-8 S/cm. Photo-response of over 105 can be obtained as the bandgap was approximately 1.90 eV. The performance of single-junction solar cells revealed a better efficiency can be obtained as the absorber bandgap was in the range of 1.83 to 1.90 eV. Further increase of the absorber bandgap may lead to the increase in bulk defect density which deteriorated the cell efficiency. Finally, a-SiOx:H/a-Si1-xGex:H tandem solar cell was fabricated with the absorber bandgap of 1.90 eV in the top cell. By matching the current between the component cells, the tandem cell efficiency of 7.38% has been achieved.

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