Investigation of the Electronic Transport in Pin Solar Cells Based on Microcrystalline Silicon by 2D Numerical Modeling

1998 ◽  
Vol 507 ◽  
Author(s):  
J. Zimmer ◽  
H. Stiebig ◽  
H. Wagner
Keyword(s):  
Numerical Modeling ◽  
Solar Cells ◽  
Grain Boundaries ◽  
Transport Properties ◽  
Amorphous Phase ◽  
Electronic Transport ◽  
Crystalline Silicon ◽  
Defect Density ◽  
Simulated Data ◽  
Microcrystalline Silicon

ABSTRACTWe investigated the transport and recombination behavior of pin solar cells based on micro- crystalline silicon (μc-Si:H). A comparison of experimental and simulated data of the dark I/V- curves, the I/V-behavior under AM1.5 illumination as well as the quantum efficiency reveals an enhanced defect density in μc-Si:H compared to c-Si which could be located as defect rich grain boundaries around the crystallites. Further, in case there is amorphous phase in the material, the distribution of a-Si:H around the crystallites is unlikely, since the electronic transport properties are disturbed, whereas an arrangement in the shape of extended areas does not affect the transport behavior significantly due to occurrence of percolation.

scholarly journals Hydrogenated Microcrystalline Silicon: From Material to Solar Cells

2000 ◽  
Vol 609 ◽  
Author(s):  
N. Wyrsch ◽  
C. Droz ◽  
L. Feitknecht ◽  
M. Goerlitzer ◽  
U. Kroll ◽  
...  
Keyword(s):  
Solar Cells ◽  
Transport Properties ◽  
Defect Density ◽  
Chemical Vapour ◽  
Impurity Content ◽  
Quality Parameter ◽  
Oxygen Impurity ◽  
Microcrystalline Silicon ◽  
Cell Efficiency ◽  
Hydrogen Dilution

ABSTRACTUndoped hydrogenated microcrystalline silicon (νc-Si:H) layers and solar cells have been deposited by plasma-enhanced chemical vapour at low temperature and at different values of VHF plasma power and silane to hydrogen dilution ratios. Transport and defect density measurements on layers suggest that structural properties (e.g. crystallite shape and size) only marginally influence the electronic transport properties. The latter are influenced strongly by the Fermi level, which depends on the oxygen impurity content. Furthermore, they are best described by the quality parameter ν0τ0 (deduced from photoconductivity and ambipolar diffusion length). Cell efficiency correlates better with νoτ0 than with the defect density as determined from subbandgap absorption. Anisotropy of the transport properties in some νc-Si:H is also demonstrated but does not seem to play a major role in νc-Si:H cells deposited at high rates under VHF glow discharge conditions.

scholarly journals Fabrication Of High Quality Qc Films Via The Route Of The Amorphous Phase

1998 ◽  
Vol 553 ◽  
Author(s):  
R. Haberkern ◽  
C. Roth ◽  
R. Knöfler ◽  
L. Schulze ◽  
P. Häussler
Keyword(s):  
Transport Properties ◽  
Amorphous Phase ◽  
Electronic Transport ◽  
Time Scale ◽  
Icosahedral Phase ◽  
Direct Transition ◽  
High Quality ◽  
Electronic Transport Properties

AbstractWe discuss the preparation of thin icosahedral films (Al-Cu-Fe and Al-Pd-Re) via the route of the amorphous (a-)phase which in some aspects is a precursor to the icosahedral phase. A direct transition from the a- to the i-phase occurs for Al-Cu-Fe films at 430°C on the time scale of minutes. The resulting films are of good quality as shown by diffraction and electronic transport properties. The surface of the resulting films is very smooth.

Mechanism of the Improvement in Microcrystalline Silicon Solar Cells by Hydrogen Plasma Treatment

2013 ◽  
Vol 773 ◽  
pp. 118-123
Author(s):  
Jing Yan Li ◽  
Xiang Bo Zeng ◽  
Hao Li ◽  
Xiao Bing Xie ◽  
Ping Yang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electric Field ◽  
Plasma Treatment ◽  
Defect Density ◽  
Hydrogen Plasma ◽  
Microcrystalline Silicon ◽  
One Dimensional ◽  
Long Wavelength ◽  
Drift Length ◽  
Experimental Improvement

We explain the experimental improvement in long wavelength response by hydrogen plasma treatment (HPT) in n/i interface. The absorption coefficient of the intrinsic microcrystalline silicon (μc-Si) is decreased in the low energy region (0.8~1.0 eV) by HPT, which indicates a lower defect density in μc-Si layer deposited with HPT than its counterpart without HPT. Simulation by one-dimensional device simulation program for the Analysis of Microelectronic and Photonic Structures (AMPS-1D) shows a higher long wavelength response in μc-Si solar cell if the defect density in intrinsic μc-Si layer is smaller. Our simulation results also disclose that the less defect density in intrinsic layer, the lower recombination rate and the higher electric field is. Higher electric field results in longer drift length which will promote collection of carriers generated by photons with long wavelength. Thus we deduce that HPT decreased defect density in absorber layer and improved the performance of μc-Si solar cells in long wavelength response.

Spin Resonance Studies on free Electrons and Defects in Microcrystalline Silicon

1994 ◽  
Vol 358 ◽  
Author(s):  
C. Malten ◽  
F. Finger ◽  
P. Hapke ◽  
T. Kulessa ◽  
C. Walker ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Grain Boundaries ◽  
Amorphous Phase ◽  
Electron Spin ◽  
Degree Of Crystallinity ◽  
Microcrystalline Silicon ◽  
Free Electrons ◽  
Conduction Band Offset ◽  
Spin Resonance ◽  
Material Points

ABSTRACTThe effect of micro-doping, defect creation, and non-steady state occupation through optical transitions on the electron spin resonance signals found in undoped and weakly doped microcrystalline silicon with a high degree of crystallinity is investigated. The experimental results are in agreement with the assignment of the resonance at g=1.9983 to conduction electrons in the crystalline grains and the resonanccs around g=2.0052 to dangling bonds in the remaining amorphous phase and at the grain boundaries. The simultaneous presence of both resonances can result from a large conduction band offset between crystalline grains and grain boundaries or the amorphous phase. The presence of conduction electron spin resonance in compensated and even p-type material points also to potential fluctuations. Free electrons in interconnected crystalline grains are in agreement with the weakly activated transport found in µc-Si:H at low temperatures.

Amorphous Silicon, Microcrystalline Silicon, and Thin-Film Polycrystalline Silicon Solar Cells

MRS Bulletin ◽  
2007 ◽  
Vol 32 (3) ◽  
pp. 219-224 ◽  
Author(s):  
Ruud E.I. Schropp ◽  
Reinhard Carius ◽  
Guy Beaucarne
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Crystalline Silicon ◽  
Low Cost ◽  
Float Glass ◽  
Film Material ◽  
Microcrystalline Silicon ◽  
Plastic Substrates ◽  
Thin Film Silicon ◽  
Amorphous Si

AbstractThin-film solar cell technologies based on Si with a thickness of less than a few micrometers combine the low-cost potential of thin-film technologies with the advantages of Si as an abundantly available element in the earth's crust and a readily manufacturable material for photovoltaics (PVs). In recent years, several technologies have been developed that promise to take the performance of thin-film silicon PVs well beyond that of the currently established amorphous Si PV technology. Thin-film silicon, like no other thin-film material, is very effective in tandem and triple-junction solar cells. The research and development on thin crystalline silicon on foreign substrates can be divided into two different routes: a low-temperature route compatible with standard float glass or even plastic substrates, and a high-temperature route (>600°C). This article reviews the material properties and technological challenges of the different thin-film silicon PV materials.

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