Use of A GAS Jet Technique to Prepare Microcrystalline Silicon Based Solar Cells at High I-Layer Deposition Rates

1999 ◽  
Vol 557 ◽  
Author(s):  
S.J. Jones ◽  
R. Crucet ◽  
X. Deng ◽  
J. Doehler ◽  
R. Kopf ◽  
...  
Keyword(s):  
Solar Cells ◽  
Peak Power ◽  
Light Exposure ◽  
Red Light ◽  
Gas Jet ◽  
Scale Production ◽  
Microcrystalline Silicon ◽  
Deposition Rates ◽  
Layer Deposition ◽  
Power Outputs

AbstractUsing a Gas Jet thin film deposition technique, microcrystalline silicon (μc-Si) materials were prepared at rates as high as 15-20 Å/s. The technique involves the use of a gas jet flow that is subjected to a high intensity microwave source. The quality of the material has been optimized through the variation of a number of deposition conditions including the substrate temperature, the gas flows, and the applied microwave power. The best films were made using deposition rates near 16 Å/s. These materials have been used as i-layers for red light absorbing, nip single-junction solar cells. Using a 610nm cutoff filter which only allows red light to strike the device, pre-light soaked currents as high as 10 mA/cm2 and 2.2-2.3% red-light pre-light soaked peak power outputs have been obtained for cells with i-layer thicknesses near 1 micron. This compares with currents of 10-11 mA/cm2 and 4% initial red-light peak power outputs obtained for high efficiency amorphous silicon germanium alloy (a-SiGe:H) devices. The AM1.5 white light efficiencies for these microcrystalline cells are 5.9-6.0%. While the efficiencies for the a-SiGe:H cells degrade by 15-20% after long term light exposure, the efficiencies for the microcrystalline cells before and after prolonged light exposure are similar, within measurement error. Considering these results, the Gas Jet deposition method is a promising technique for the deposition of μc-Si solar cells due to the ability to achieve reasonable stable efficiencies for cells at i-layer deposition rates (16 Å/s) which make large-scale production economically feasible.

Preparation of Microcrystalline Silicon Based Solar Cells at High i-layer Deposition Rates Using a Gas Jet Technique

2000 ◽  
Vol 609 ◽  
Author(s):  
S.J. Jones ◽  
R. Crucet ◽  
X. Deng ◽  
D.L. Williamson ◽  
M. Izu
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Red Light ◽  
Layer Growth ◽  
Gas Jet ◽  
Similar Amount ◽  
Microcrystalline Silicon ◽  
Deposition Rates ◽  
Silicon Based ◽  
Microcrystalline Materials

ABSTRACTA Gas Jet technique has been used to prepare microcrystalline silicon (μc-Si) thin films at deposition rates as high as 20 Å/s. The films have microcrystal sizes between 80 and 120 Å with a heterogeneous microstructure containing regions with columnar growth and other regions with a more randomly oriented microstructure. These materials have been used as i-layers for nip single-junction solar cells. The high deposition rates allow for fabrication of the required thicker μc-Si i-layers in a similar amount of time to those used for high quality a-SiGe:H i-layers (rates of 1-3 Å/s). Using a 610nm cutoff filter which only allows red light to strike the device, pre-light soaked short circuit currents of 8-10 mA/cm2 and 2.7% red-light efficiencies have been obtained while AM1.5 white light efficiencies are above 7%. These efficiencies are higher than those typically obtained for μc-Si cells prepared at the high i-layer growth rates using other deposition techniques. After 1000 h. of light soaking, the efficiencies on average degrade only by 2-5% (stabilized efficiencies of 2.6%) consistent with the expected high stability with the microcrystalline materials. The small amount of degradation compares with the 15-17% degradation in efficiencies for a-SiGe:H cells subjected to similar irradiation treatments (final light-soaked red light efficiencies of 3.2%). Improvements in the cell efficiencies may come through an understanding of the role that columnar microstructure and void structure plays in determining the device performance.

Improved Efficiency of Single Junction Microcrystalline Silicon n-i-p Solar Cells with an i-Layer Made by Hot-Wire CVD

2007 ◽  
Vol 989 ◽  
Author(s):  
Hongbo Li ◽  
Ronald H.J. Franken ◽  
Robert L. Stolk ◽  
C. H.M. van der Werf ◽  
Jan-Willem A. Schuttauf ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Solar Cells ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Hot Wire ◽  
Microcrystalline Silicon ◽  
Single Junction ◽  
Layer Deposition ◽  
P Cells

AbstractThe influence of the surface roughness of Ag/ZnO coated substrates on the AM1.5 J-V characteristics of microcrystalline silicon (μc-Si:H) solar cells with an i-layer made by the hot-wire chemical vapour deposition (HWCVD) technique is discussed. Cells deposited on substrates with an intermediate rms roughness show the highest efficiency. When using reverse hydrogen profiling during i-layer deposition, an efficiency of 8.5 % was reached for single junction μc-Si:H n-i-p cells, which is the highest for μc-Si:H n-i-p cells with a hot-wire i-layer.

Microcrystalline Silicon for Solar Cells at High Deposition Rates by Hot Wire Cvd

2002 ◽  
Vol 715 ◽  
Author(s):  
R. E. I. Schropp ◽  
Y. Xu ◽  
E. Iwaniczko ◽  
G. A. Zaharias ◽  
A. H. Mahan
Keyword(s):  
Solar Cells ◽  
Substrate Temperature ◽  
Volume Fraction ◽  
Silicon Layer ◽  
Hot Wire ◽  
Crystalline Volume Fraction ◽  
Microcrystalline Silicon ◽  
Deposition Rates ◽  
Deposition Parameters ◽  
Si Films

AbstractWe have explored which deposition parameters in Hot Wire CVD have the largest impact on the quality of microcrystalline silicon (μc-Si) made at deposition rates (Rd) < 10 Å/s for use in thin film solar cells. Among all parameters, the filament temperature (Tfil) appears to be crucial for making device quality films. Using two filaments and a filament-substrate spacing of 3.2 cm, μc-Si films, using seed layers, can be deposited at high Tfil (∼2000°C) with a crystalline volume fraction < 70-80 % at Rd's < 30 Å/s. Although the photoresponse of these layers is high (< 100), they appear not to be suitable for incorporation into solar cells, due to their porous nature. n-i-p cells fabricated on stainless steel with these i-layers suffer from large resistive effects or barriers, most likely due to the oxidation of interconnected pores in the silicon layer. The porosity is evident from FTIR measurements showing a large oxygen concentration at ∼1050 cm-1, and is correlated with the 2100 cm-1 signature of most of the Si-H stretching bonds. Using a Tfil of 1750°C, however, the films are more compact, as seen from the absence of the 2100 cm-1 SiH mode and the disappearance of the FTIR Si-O signal, while the high crystalline volume fraction (< 70-80 %) is maintained. Using this Tfil and a substrate temperature of 400°C, we obtain an efficiency of 4.9 % for cells with a Ag/ZnO back reflector, with an i-layer thickness of only ∼0.7 μm. High values for the quantum efficiency extend to very long wavelengths, with values of 33 % at 800 nm and 15 % at 900 nm, which are unequalled by a-SiGe:H alloys. Further, by varying the substrate temperature to enable deposition near the microcrystalline to amorphous transition (‘edge’) and incorporating variations in H2 dilution during deposition of the bulk, efficiencies of 6.0 % have been obtained. The Rd's of these i-layers are 8-10 Å/s, and are the highest to date obtained with HWCVD for microcrystalline layers used in cells with efficiencies of ∼6 %.

scholarly journals Microcrystalline silicon absorber layers prepared at high deposition rates for thin-film tandem solar cells

2013 ◽  
Vol 4 ◽  
pp. 45201 ◽  
Author(s):  
S. Michard ◽  
V. Balmes ◽  
M. Meier ◽  
A. Lambertz ◽  
T. Merdzhanova ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Microcrystalline Silicon ◽  
Deposition Rates ◽  
Tandem Solar Cells

Preparation of Triple-Junction A-Si:H NIP Based Solar Cells at Deposition Rates of 10 Å/s using a Very High Frequency Technique

1999 ◽  
Vol 557 ◽  
Author(s):  
S.J. Jones ◽  
X. Deng ◽  
T. Liu ◽  
M. Izu
Keyword(s):  
Solar Cells ◽  
Deposition Rate ◽  
Triple Junction ◽  
High Frequency ◽  
Rf Plasma ◽  
Very High Frequency ◽  
Deposition Rates ◽  
Single Junction ◽  
Layer Deposition ◽  
Very High

AbstractIn an effort to find an alternative deposition method to the standard low deposition rate 13.56 M-z PECVD technique, the feasibility of using a 70 MiHz rf plasma frequency to prepare a-Si:H based i-layer materials at high rates for nip based triple-junction solar cells has been tested. As a prelude to multi-junction cell fabrication, the deposition conditions used to make single-junction a-Si:H and a-SiGe:H cells using this Very High Frequency (VHF) method have been varied to optimize the material quality and the cell efficiencies. It was found that the efficiencies and the light stability for both a-Si:H and a-SiGe:H single-junction cells remain relatively constant as the i-layer deposition rate is varied from 1 to 10 Å/s. Also these stable efficiencies are similar to those for cells made at low deposition rates (1 Å/s) using the standard 13.56 MHz PECVD technique and the same deposition equipment. Using the knowledge obtained in the fabrication of the single-junction devices, a-Si:H/a-SiGe:H/a-SiGe:H triple-junction solar cells have been fabricated with all of the i-layers prepared using the VHF technique and deposition rates near 10 Å/s. Thin doped layers for these devices were prepared using the standard 13.56 MIHz rf frequency and deposition rates near 1 Å/s. Pre-light soaked efficiencies of greater than 10% have been obtained for these cells prepared at the high rates. In addition, after 600 hrs. of light soaking under white light conditions, the cell efficiencies degraded by only 10-13%, values similar to the degree of degradation for high efficiency triple-junction cells made by the standard 13.56 MiHz method using i-layer deposition rates near 1 Å/s. Thus, use of this VHF method in the production of large area a-Si:H based multi-junction solar modules will allow for higher i-layer deposition rates, higher module throughput and reduced module cost.

Preparation of a-Si:H and a-SiGe:H I-Layers for Nip Solar Cells at High Deposition Rates Using a Very High Frequency Technique

1998 ◽  
Vol 507 ◽  
Author(s):  
S.J. Jones ◽  
X. Deng ◽  
T. Liu ◽  
M. Izu
Keyword(s):  
Solar Cells ◽  
Deposition Rate ◽  
High Frequency ◽  
High Efficiency ◽  
High Deposition Rate ◽  
Very High Frequency ◽  
Deposition Rates ◽  
Single Junction ◽  
Layer Deposition ◽  
Very High

ABSTRACTThe 70 MHz Plasma Enhance Chemical Vapor Deposition (PECVD) technique has been tested as a high deposition rate (10 A/s) process for the fabrication of a-Si:H and a-SiGe:H alloy ilayers for high efficiency nip solar cells. As a prelude to multi-junction cell fabrication, the deposition conditions used to make single-junction a-Si:H and a-SiGe:H cells using this Very High Frequency (VHF) method have been varied to optimize the material quality and the cell efficiencies. It was found that the efficiencies and the light stability for a-Si:H single-junction cells can be made to remain relatively constant as the i-layer deposition rate is varied from 1 to 10 Å/s. Also these stable efficiencies are similar to those for cells made at low deposition rates (1 Å/s) using the standard 13.56 MHz PECVD technique. For the a-SiGe:H cells of the same i-layer thickness, use of the VHF technique leads to cells with higher currents and an ability to more easily current match triple-junction cells prepared at high deposition rates which should lead to higher multi-junction efficiencies. Thus, use of this VHF method in the production of large area a- Si:H based multi-junction solar modules will allow for higher i-layer deposition rates, higher manufacturing throughput and reduced module cost.

High Efficiency Solar Cells with Intrinsic Microcrystalline Silicon Absorbers Deposited at High Rates by VHF-PECVD

2005 ◽  
Vol 862 ◽  
Author(s):  
Yaohua Mai ◽  
Stefan Klein ◽  
Reinhard Carius ◽  
Xinhua Geng ◽  
Friedhelm Finger
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Chemical Vapor ◽  
Microcrystalline Silicon ◽  
Very High Frequency ◽  
Deposition Rates ◽  
Glass Substrates ◽  
High Efficiency Solar Cells ◽  
High Frequency Plasma ◽  
Frequency Plasma

AbstractIntrinsic microcrystalline silicon (μc-Si:H ) was prepared at high deposition rates (RD) by very high frequency plasma-enhanced chemical vapor deposition (PECVD) working at high-pressure high-power (hphP). The material has similar electrical and optical properties as μc-Si:H material deposited at low rates by low-pressure low-power PECVD, apart from a more pronounced structure in-homogeneity along the growth axis for material deposited on glass substrates. With optimized deposition conditions high efficiency solar cells can be grown with deposition rates of up to 15 Å/s without deterioration of the performance as a function of RD. A high conversion efficiency of 9.8 % was obtained for a single junction μc-Si:H p-i-n solar cell at a deposition rate of RD = 11 Å/s.

scholarly journals Artificial complementary chromatic acclimation gene expression system in Escherichia coli

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Dwi Ariyanti ◽  
Kazunori Ikebukuro ◽  
Koji Sode
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Light Exposure ◽  
Expression System ◽  
Red Light ◽  
Green Light ◽  
Light Illumination ◽  
Multiple Gene ◽  
Gene Expression System ◽  
Chromatic Acclimation

Abstract Background The development of multiple gene expression systems, especially those based on the physical signals, such as multiple color light irradiations, is challenging. Complementary chromatic acclimation (CCA), a photoreversible process that facilitates the control of cellular expression using light of different wavelengths in cyanobacteria, is one example. In this study, an artificial CCA systems, inspired by type III CCA light-regulated gene expression, was designed by employing a single photosensor system, the CcaS/CcaR green light gene expression system derived from Synechocystis sp. PCC6803, combined with G-box (the regulator recognized by activated CcaR), the cognate cpcG2 promoter, and the constitutively transcribed promoter, the PtrcΔLacO promoter. Results One G-box was inserted upstream of the cpcG2 promoter and a reporter gene, the rfp gene (green light-induced gene expression), and the other G-box was inserted between the PtrcΔLacO promoter and a reporter gene, the bfp gene (red light-induced gene expression). The Escherichia coli transformants with plasmid-encoded genes were evaluated at the transcriptional and translational levels under red or green light illumination. Under green light illumination, the transcription and translation of the rfp gene were observed, whereas the expression of the bfp gene was repressed. Under red light illumination, the transcription and translation of the bfp gene were observed, whereas the expression of the rfp gene was repressed. During the red and green light exposure cycles at every 6 h, BFP expression increased under red light exposure while RFP expression was repressed, and RFP expression increased under green light exposure while BFP expression was repressed. Conclusion An artificial CCA system was developed to realize a multiple gene expression system, which was regulated by two colors, red and green lights, using a single photosensor system, the CcaS/CcaR system derived from Synechocystis sp. PCC6803, in E. coli. The artificial CCA system functioned repeatedly during red and green light exposure cycles. These results demonstrate the potential application of this CCA gene expression system for the production of multiple metabolites in a variety of microorganisms, such as cyanobacteria.

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