scholarly journals Model for Staebler-Wronski Degradation Deduced from Long-Term, Controlled Light-Soaking Experiments

2000 ◽  
Vol 609 ◽  
Author(s):  
Bolko von Roedern ◽  
Joseph A. del Cueto
Keyword(s):  
Light Intensity ◽  
Amorphous Silicon ◽  
Operating Conditions ◽  
Degradation Mechanisms ◽  
Time Constants ◽  
Photovoltaic Modules ◽  
History Of ◽  
Exposure History ◽  
Operating History

ABSTRACTLong-term light-soaking experiments of amorphous silicon photovoltaic modules have now established that stabilization of the degradation occurs at levels that depend significantly on the operating conditions, as well as on the operating history of the modules. We suggest that stabilization occurs because of the introduction of degradation mechanisms with different time constants and annealing activation energies, depending on the exposure conditions. Stabilization will occur once a sufficient accumulation of different degradation mechanisms occurs. We find that operating module temperature during light-soaking is the most important parameter for determining stabilized performance. Next in importance is the exposure history of the device. The precise value of the light intensity seems least important in determining the stabilized efficiency, as long as its level is a significant fraction of 1-sun.

scholarly journals Mechanical Degradation Analysis of an Amorphous Silicon Solar Module

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4126
Author(s):  
Gilbert Osayemwenre ◽  
Edson Meyer
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Adhesion Force ◽  
Structural Defects ◽  
Mechanical Degradation ◽  
Solar Module ◽  
Photovoltaic Modules ◽  
Degradation Analysis ◽  
Defective Region

This work examines the degradation of photovoltaic modules. It assesses the structural defects of amorphous silicon solar cells, which result from mechanical stress at nanoscale level. Firstly, it analyses the interface morphology, deformation, and internal delamination of a single junction amorphous silicon solar module. Secondly, it explores the interface deformation of the layers of the defective region of the module with some statistical tools including root mean root (RSM) and arithmetic mean (Rq). It used the aforementioned tools to demonstrate the effect of microstructural defects on the mechanical behaviour of the entire layers of the module. The study established that the defect observed in the module, emanated from long-term degradation of the a-Si solar cells after years of exposure to various light and temperature conditions. It tested the mechanism of mechanical degradation and its effect on the reliability and stability of the defective and non-defective regions of the module with adhesion force characterisation.

scholarly journals Behavioral data of thin-film single junction amorphous silicon (a-Si) photovoltaic modules under outdoor long term exposure

Data in Brief ◽  
2016 ◽  
Vol 7 ◽  
pp. 366-371 ◽  
Author(s):  
Sofiane Kichou ◽  
Santiago Silvestre ◽  
Gustavo Nofuentes ◽  
Miguel Torres-Ramírez ◽  
Aissa Chouder ◽  
...  
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Behavioral Data ◽  
Single Junction ◽  
Photovoltaic Modules

Evaluation of PBTS and NBTS in SiC MOS Using In Situ Charge Pumping Measurements

2013 ◽  
Vol 740-742 ◽  
pp. 545-548 ◽  
Author(s):  
Daniel B. Habersat ◽  
Aivars J. Lelis ◽  
Ronald Green ◽  
Mooro El
Keyword(s):  
Charge Trapping ◽  
Operating Conditions ◽  
Degradation Mechanisms ◽  
Power Devices ◽  
Charge Pumping ◽  
Long Term Stability ◽  
Accelerated Degradation ◽  
Mos Devices

Since power devices such as DMOSFETs will operate at higher temperatures with accelerated degradation mechanisms, it is essential to understand the effects of typical operating conditions for power electronics applications. We have found that SiC MOSFETs when gate-biased at 150 °C show an increasing charge pumping current over time, suggesting that interface traps (or perhaps near-interface oxide traps) are being created under these conditions. This trapping increase occurs slightly above linear-with-log-time and mimics previously observed threshold voltage instabilities, though a causal relationship has not yet been determined. We found the charge trapping after 104 s of BTS increased at a rate of 1x1011 cm-2/dec for NBTS (-3 MV/cm), 0.7x1011 cm-2/dec for PBTS (3 MV/cm), and 0.3x1011 cm-2/dec when grounded. The observed increase in charge trapping has negative implications for the long term stability and reliability of SiC MOS devices under operating conditions.

scholarly journals Outdoor testing of photovoltaic modules during summer in Taxila, Pakistan

2016 ◽  
Vol 20 (1) ◽  
pp. 165-173 ◽  
Author(s):  
Hafiz Ali ◽  
Mubashar Mahmood ◽  
Muhammad Bashir ◽  
Muzaffar Ali ◽  
Aysha Siddiqui
Keyword(s):  
Amorphous Silicon ◽  
Operating Conditions ◽  
Performance Ratio ◽  
Published Data ◽  
Photovoltaic Modules ◽  
Efficiency Performance ◽  
Higher Temperature ◽  
Low Efficiency ◽  
And Performance ◽  
Module Efficiency

An experimental study has been carried out to measure the performance of commercially available photovoltaic modules during summer months in the climate of Taxila, near the capital of Pakistan. The modules used in the study are monocrystalline silicon (c-Si), polycrystalline silicon (p-Si) and single junction amorphous silicon (a-Si). The analysis has been focused on the measurement of module efficiency, performance ratio and temperature of each module at actual operating conditions using outdoor monitoring facility. The measured results are compared with the already published data of peak winter month at the same site. Overall, the monocrystalline module showed high average module efficiency while amorphous silicon module was better in term of average performance ratio. Furthermore, the module efficiency and performance ratio has shown decreasing trend with increase of module temperature. It was found that modules have much higher temperature in summer months (about 20?C higher) and showed low efficiency and performance ratio than peak winter month. The average ambient temperature varied from 18.1?C to 38.6?C from winter to summer.

Characterization of degradation and evaluation of model parameters of amorphous silicon photovoltaic modules under outdoor long term exposure

Energy ◽  
2016 ◽  
Vol 96 ◽  
pp. 231-241 ◽  
Author(s):  
Sofiane Kichou ◽  
Santiago Silvestre ◽  
Gustavo Nofuentes ◽  
Miguel Torres-Ramírez ◽  
Aissa Chouder ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Model Parameters ◽  
Photovoltaic Modules

Atypical Femoral Fracture in McCune-Albright Syndrome

2020 ◽  
Vol 7 (3) ◽  
pp. 147-152
Author(s):  
Salman Ghaffari ◽  
◽  
Mehran Razavipour ◽  
Parastoo Mohammad Amini ◽  
◽  
...  
Keyword(s):  
Femoral Fracture ◽  
Dynamic Compression ◽  
Plate Fixation ◽  
Medullary Canal ◽  
Mccune Albright Syndrome ◽  
Café Au Lait Spots ◽  
History Of ◽  
Albright Syndrome ◽  
Mccune Albright

McCune-Albright Syndrome (MAS) is characterized by endocrinopathies, café-au-lait spots, and fibrous dysplasia. Bisphosphonates are the most prescribed treatment for reducing the pain but their long-term use has been associated with atypical fractures of cortical bones like femur in patients. We present a 23-year-old girl diagnosed with MAS. She had an atypical mid-shaft left femoral fracture that happened during simple walking. She also had a history of long-term use of alendronate. Because of the narrow medullary canal, we used 14 holes hybrid locking plate for the lateral aspect of the thigh to fix the fracture and 5 holes dynamic compression plate (instead of the intramedullary nail) in the anterior surface to double fix it, reducing the probability of device failure. With double plate fixation and discontinuation of alendronate, the complete union was achieved five months after surgery

European Integration

2020 ◽  
Author(s):  
Johann P. Arnason
Keyword(s):  
European Integration ◽  
Eastern European ◽  
The European Union ◽  
Historical Processes ◽  
History Of ◽  
External Conditions ◽  
Eastern European Countries ◽  
Totalitarian Regimes ◽  
The Eu

Different understandings of European integration, its background and present problems are represented in this book, but they share an emphasis on historical processes, geopolitical dynamics and regional diversity. The introduction surveys approaches to the question of European continuities and discontinuities, before going on to an overview of chapters. The following three contributions deal with long-term perspectives, including the question of Europe as a civilisational entity, the civilisational crisis of the twentieth century, marked by wars and totalitarian regimes, and a comparison of the European Union with the Habsburg Empire, with particular emphasis on similar crisis symptoms. The next three chapters discuss various aspects and contexts of the present crisis. Reflections on the Brexit controversy throw light on a longer history of intra-Union rivalry, enduring disputes and changing external conditions. An analysis of efforts to strengthen the EU’s legal and constitutional framework, and of resistances to them, highlights the unfinished agenda of integration. A closer look at the much-disputed Islamic presence in Europe suggests that an interdependent radicalization of Islamism and the European extreme right is a major factor in current political developments. Three concluding chapters adopt specific regional perspectives. Central and Eastern European countries, especially Poland, are following a path that leads to conflicts with dominant orientations of the EU, but this also raises questions about Europe’s future. The record of Scandinavian policies in relation to Europe exemplifies more general problems faced by peripheral regions. Finally, growing dissonances and divergences within the EU may strengthen the case for Eurasian perspectives.

The natural history of pituitary apoplexy: long term follow-up study

2019 ◽  
Author(s):  
Ayesha Shaikh ◽  
Natasha Shrikrishnapalasuriyar ◽  
Giselle Sharaf ◽  
David Price ◽  
Maneesh Udiawar ◽  
...  
Keyword(s):  
Natural History ◽  
Pituitary Apoplexy ◽  
Follow Up Study ◽  
Long Term Follow Up ◽  
History Of

Use of Transparent Conductive Oxide Materials with Low Indices of Refraction in Amorphous Silicon-Based Solar Cell Technology

2005 ◽  
Vol 862 ◽  
Author(s):  
Scott J. Jones ◽  
Joachim Doehler ◽  
Tongyu Liu ◽  
David Tsu ◽  
Jeff Steele ◽  
...  
Keyword(s):  
Solar Cell ◽  
Amorphous Silicon ◽  
Transparent Conductive Oxide ◽  
Open Circuit ◽  
Long Term Stability ◽  
Back Reflectors ◽  
Stability Issues ◽  
Silicon Based ◽  
Solar Cell Technology

AbstractNew types of transparent conductive oxides with low indices of refraction have been developed for use in optical stacks for the amorphous silicon (a-Si) solar cell and other thin film applications. The alloys are ZnO based with Si and MgF added to reduce the index of the materials through the creation of SiO2 or MgF2, with n=1.3-1.4, or the addition of voids in the materials. Alloys with 12-14% Si or Mg have indices of refraction at λ=800nm between 1.6 and 1.7. These materials are presently being used in optical stacks to enhance light scattering by Al/multi-layer/ZnO back reflectors in a-Si based solar cells to increase light absorption in the semiconductor layers and increase open circuit currents and boost device efficiencies. In contrast to Ag/ZnO back reflectors which have long term stability issues due to electromigration of Ag, these Al based back reflectors should be stable and usable in manufactured PV products. In this manuscript, structural properties for the materials will be reported as well as the performance of solar cell devices made using these new types of materials.

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