Hidden parameters in the plasma deposition of microcrystalline silicon solar cells

2007 ◽  
Vol 22 (7) ◽  
pp. 1767-1774 ◽  
Author(s):  
M.N. van den Donker ◽  
B. Rech ◽  
R. Schmitz ◽  
J. Klomfass ◽  
G. Dingemans ◽  
...  
Keyword(s):  
Solar Cells ◽  
Process Parameters ◽  
Gas Flow ◽  
Plasma Deposition ◽  
Deposition Process ◽  
Additional Parameter ◽  
Hydrogen Dilution ◽  
The Stability

The effect of process parameters on the plasma deposition of μc-Si:H solar cells is reviewed in this article. Several in situ diagnostics are presented, which can be used to study the process stability as an additional parameter in the deposition process. The diagnostics were used to investigate the stability of the substrate temperature during deposition at elevated power and the gas composition during deposition at decreased hydrogen dilution. Based on these investigations, an updated view on the role of the process parameters of plasma power, heater temperature, total gas flow rate, and hydrogen dilution is presented.

An in situ cross-linked 1D/3D perovskite heterostructure improves the stability of hybrid perovskite solar cells for over 3000 h operation

2020 ◽  
Vol 13 (11) ◽  
pp. 4344-4352
Author(s):  
Ning Yang ◽  
Cheng Zhu ◽  
Yihua Chen ◽  
Huachao Zai ◽  
Chenyue Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Perovskite Solar Cells ◽  
Perovskite Solar Cell ◽  
Operational Stability ◽  
Hybrid Perovskite ◽  
The Stability

An in situ cross-linked 1D/3D perovskite heterostructure achieved a perovskite solar cell with a 21.19% PCE and operational stability over 3000 hours.

The Role of Demixing and Crystallization Kinetics on the Stability of Non‐Fullerene Organic Solar Cells

2020 ◽  
Vol 32 (49) ◽  
pp. 2005348
Author(s):  
Huawei Hu ◽  
Masoud Ghasemi ◽  
Zhengxing Peng ◽  
Jianquan Zhang ◽  
Jeromy James Rech ◽  
...  
Keyword(s):  
Solar Cells ◽  
Crystallization Kinetics ◽  
Organic Solar Cells ◽  
The Stability

Evaluation of Ar-Diluted Silane PECVD for Thin Film Si:H Based Solar Cells

2004 ◽  
Vol 808 ◽  
Author(s):  
J. A. Anna Selvan ◽  
Yuan-Min Li ◽  
Liwei Li ◽  
Alan E. Delahoy
Keyword(s):  
Solar Cells ◽  
Spectral Response ◽  
Nanocrystalline Silicon ◽  
Thin Layers ◽  
Dilution Method ◽  
Critical Question ◽  
Long Wavelength ◽  
Hydrogen Dilution ◽  
Porous Microstructure ◽  
The Stability

ABSTRACTDilution by Ar of silane plasma has been reported to increase the stability of a-Si:H films. A critical question is whether Ar diluted i-layers offer higher stabilized solar cell efficiencies than the conventional hydrogen dilution method. We have fabricated a-Si:H p-i-n solar cells with RF-PECVD i-layers by Ar dilution of silane. Ar dilution ratio (ADR, Ar/SiH4), RF power,pressure, and i-layer thickness were varied. At low ADR < 20, such solar cells show comparable initial efficiencies and stability as those devices having H2-diluted i-layers of similar thickness. For cells made with ADR > 20, the initial efficiency decreases dramatically with further increase in Ar dilution, and light soaking causes only mild changes in efficiencies. The stabilized efficiencies of cells made with high ADR are inferior to the cells produced with low ADR or cells prepared by H2 dilution. Further, Voc of solar cells made with high ADR (> 50) decreases substantially in ambient, indicating a porous microstructure susceptible to oxidation. While thermal annealing improves the Voc, a full recovery of Voc is made by accelerated light soaking.The combination of high power and high ADR can lead to nanocrystalline silicon (nc-Si:H) growth, although nucleation is much more difficult to attain by the Ar dilution method compared to hydrogen dilution. We have succeeded in fabricating p-i-n solar cells with nc-Si:H i-layers prepared by the Ar dilution approach. The double dilution by Ar and hydrogen of silane (Ar+H2+SiH4) can result in nc-Si:H i-layers with enhanced long wavelength spectral response compared to devices incorporating nc-Si:H i-layers grown by H2 dilution only. The nc-Si:H solar cells with Ar+H2 diluted i-layers exhibit no light-induced degradation.Using energetic Ar-rich plasma, in a process much simpler than the traditional nc-Si:H technique, doped a-Si:H thin layers can be prepared to form excellent tunnel junctions for multi-junction solar cells. We demonstrate such a novel, non-contaminating tunnel junction in tandem a-Si/a-Si and a-Si/nc-Si solar cells entirely fabricated in a single-chamber RF-PECVD system.

scholarly journals The role of carbon-based materials in enhancing the stability of perovskite solar cells

2020 ◽  
Vol 13 (5) ◽  
pp. 1377-1407 ◽  
Author(s):  
Mahboubeh Hadadian ◽  
Jan-Henrik Smått ◽  
Juan-Pablo Correa-Baena
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
The Stability ◽  
Carbon Based

Enhancing the stability of perovskite solar cells is crucial to the deployment of this technology. Carbon-based materials are promising candidates for providing long-term stable perovskite solar cells suitable for commercialization.

Vapor-Phase Catalyst Delivery Method for Growing SiC Nanowires

2013 ◽  
Vol 740-742 ◽  
pp. 209-212 ◽  
Author(s):  
Rooban Venkatesh K.G. Thirumalai ◽  
Bharat Krishnan ◽  
Albert Davydov ◽  
Joseph Neil Merrett ◽  
Yaroslav Koshka
Keyword(s):  
Vapor Phase ◽  
Gas Flow ◽  
Substrate Surface ◽  
Metal Catalyst ◽  
Catalyst Nanoparticles ◽  
Sic Nanowires ◽  
Cvd Growth ◽  
Hot Zone

A method was developed for growing SiC nanowires without depositing a metal catalyst on the targeted surfaces prior to the CVD growth. The proposed method utilizes in-situ vapor-phase catalyst delivery via sublimation of the catalyst from a metal source placed in the hot zone of the CVD reactor, followed by condensation of the catalyst-rich vapor on the bare substrate surface to form the catalyst nanoparticles. The vapor-phase catalyst delivery and the resulting nanowire density was found to be influenced by both the gas flow rate and the catalyst diffusion through the boundary layer above the catalyst source. The origin of undesirable bushes of nanowires and the role of the C/Si ratio were established.

Threshold Value of Particle Concentration in EPD: Experimental Evidence with TiO2 Organic Suspensions

2009 ◽  
Vol 412 ◽  
pp. 51-56 ◽  
Author(s):  
Simona Radice ◽  
Stefano Mischler ◽  
Johann Michler
Keyword(s):  
Particle Concentration ◽  
Deposition Time ◽  
Threshold Value ◽  
Deposition Process ◽  
Suspension Systems ◽  
Limit Value ◽  
Coating Formation ◽  
Concentration Threshold

This study was triggered by our experience on electrophoretic deposition (EPD) with different suspension systems showing evidence of a particle concentration threshold, below which no deposit was formed. In this study, the role of particle concentration in the mechanism of EPD was investigated with a model system, consisting of isopropanol suspensions with TiO2 nanosized particles (d50 = 130 nm). The investigated concentration range was 0.01 - 0.4 vol% TiO2. Constant voltage EPD tests with variable particle concentration were performed for 1 min under different applied voltages (25 - 300 V corresponding to 62.5 - 750 V/cm). A longer deposition time (30 min) was tested for a lower concentration value (0.003 vol% TiO2). The deposition process was evaluated in situ by means of the current measured during EPD. The deposits obtained were characterized by weight and profile measurements and scanning electron microscope (SEM). The results confirmed the finding of a lower limit value of particle concentration, determining a threshold in the formation of an EPD coating. Above this threshold, proportionality between deposited mass and particle concentration was observed, in agreement with the equation of Hamaker. Below this threshold, the proportionality was lost with evidence of a lack of coating formation. A possible interpretation for this experimental finding was provided.

Stability of Single and Tandem Junction A-Si:H Solar Cells Grown using the ECR Process

1997 ◽  
Vol 467 ◽  
Author(s):  
Vikram L. Dalal ◽  
Tim Maxson ◽  
Robert Girvan ◽  
Sohail Haroon
Keyword(s):  
Solar Cells ◽  
Stability Studies ◽  
Stability Tests ◽  
High Hydrogen ◽  
Single Junction ◽  
Hydrogen Dilution ◽  
The Stability

ABSTRACTWe report on the fabrication and stability tests of single junction a-Si:H, and tandem junction a-Si:H/a-Si:H solar cells using the ECR process under high hydrogen dilution (H-ECR process). We show that devices with high fill factors can be made using the H-ECR process. We also report on the stability studies of the solar cells under 1 and 2-sun illumination conditions. The solar cells show very little degradation even after 500 hours of illumination under 2 x sunlight illumination.

scholarly journals Fundamental Role Of The H2A.Z C-Terminal Tail In The Formation Of Constitutive Heterochromatin

2021 ◽  
Author(s):  
László Imre ◽  
Péter Nánási ◽  
Rosevalentine Bosire ◽  
Ágota Csóti ◽  
Kata Nóra Enyedi ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Constitutive Heterochromatin ◽  
Large Fraction ◽  
Gene Expression Pattern ◽  
Histone Variant ◽  
Unusual Behavior ◽  
Isoform Specificity ◽  
The Stability

ABSTRACTNucleosome stability, a crucial determinant of gene regulation, was measured in a robust in situ assay to assess the molecular determinants of the stability of H2A.Z-containig nucleosomes. Surprisingly, a large fraction of H2A.Z detected by three different antibodies was released from the nucleosomes by salt together with H3, and was associated with H3K9me3 but not with H3K27me3 marked nucleosomes. This unusual behavior relied on the presence of the unstructured C-terminal chain of the histone variant, rather than on isoform specificity, posttranslational modifications or binding of the reader protein PWWPA2, as determined using cell lines expressing only particular forms of the variant. In the absence of this tail, or upon addition of an excess of the tail peptide to the nuclei of control cells, the canonical H2A-like stability features were readily restored and most of the H2A.Z-containing nucleosomes left the periphery and ended up in scattered foci in the nuclei. Concomitantly, the H3K9me3-marked constitutive heterochromatin was also dispersed, what was accompanied by increased overall nuclease sensitivity and significantly enhanced binding of intercalating dyes to the DNA. The DT40 cells expressing the tailless H2A.Z showed marked differences in their gene expression pattern and were distinguished by compromised DNA damage response. Thus, interactions involving a short H2A.Z peptide chain simultaneously determine the stability and accessibility features of chromatin involving the nucleosomes containing this histone variant and the localization of these large chromatin regions in the nucleus. Our data suggest that H2A.Z can function in both heterochromatic and in euchromatic scenarios depending on the molecular interactions involving its C-terminal unstructured tail, shedding light on the enigmatic double-faced character of this histone variant.

scholarly journals Ambient blade coating of mixed cation, mixed halide perovskites without dripping: in situ investigation and highly efficient solar cells

2020 ◽  
Vol 8 (3) ◽  
pp. 1095-1104 ◽  
Author(s):  
Ming-Chun Tang ◽  
Yuanyuan Fan ◽  
Dounya Barrit ◽  
Xiaoming Chang ◽  
Hoang X. Dang ◽  
...  
Keyword(s):  
Solar Cells ◽  
X Ray ◽  
X Ray Scattering ◽  
Mixed Cation ◽  
In Situ Investigation ◽  
Halide Perovskites ◽  
Halide Perovskite ◽  
Blade Coating

Blade coating of mixed cation, mixed halide perovskite films is investigated using in situ X-ray scattering to investigate the role of formulations and processing routes and eliminate the need for anti-solvent dripping.

The Effects of Substitutional Additions on Creep Behavior of Tetragonal and Hexagonal Nb-Silicides

2002 ◽  
Vol 753 ◽  
Author(s):  
B. P. Bewlay ◽  
C. L. Briant ◽  
E. T. Sylven ◽  
M. R. Jackson
Keyword(s):  
Creep Behavior ◽  
High Strength ◽  
Aircraft Engine ◽  
Great Promise ◽  
Silicide Phase ◽  
Monolithic Phases ◽  
Phase Ordering ◽  
The Stability

ABSTRACTNb-silicide based in-situ composites combine a ductile Nb-based solid solution with high-strength silicides, and they show great promise for aircraft engine applications. The Nb-silicide controls the high-temperature creep behavior of the composite. Previous work has shown that the silicide composition has an important effect on the creep rate, with particular attention on the role of Ti and Hf additions. The aim of the present study is to understand the effects of the substitutional elements on the stability of the silicide phase, ordering in the crystal lattice, including the hP16-tI32 transition, and the creep behavior of the monolithic phases. To pursue this goal monolithic alloys with a range of compositions were prepared and the creep rates were measured at temperatures of 1100–1350°C. The stress sensitivities of the creep rates of the monolithic phases were also determined.

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