This document describes research on fabricating an all-aluminum p-type silicon solar cell. The goal was to replace silver, a costly material, with the more abundant aluminum. The fabricated cell had lower efficiency than a reference cell using silver, due to higher resistances. To improve performance, the researchers need to optimize the fabrication process and device specifications to reduce resistances at interfaces and contamination. Overall, the study demonstrated the concept but further work is needed to enhance the cell's efficiency.
This ppt gives you the basic introduction, talks about it's inception, the basic physics behind it and mainly the fabrication process and after that it discusses the uses and future prospects of it.
This ppt gives you the basic introduction, talks about it's inception, the basic physics behind it and mainly the fabrication process and after that it discusses the uses and future prospects of it.
In this Presentation on solar cell is most effect for student of class 12
Contents:
Introduction to Solar Cells .
* The working principal of a solar cell .
* Types of solar cells.
* Working and construction.
* Benefit and disadvantages.
* application.
* Summary.
Overview of advantages and fabrication of solar cells made from silicon nanowires. IT includes few slides of conventional solar cells and benefits of using silicon nanowire.
In this Presentation on solar cell is most effect for student of class 12
Contents:
Introduction to Solar Cells .
* The working principal of a solar cell .
* Types of solar cells.
* Working and construction.
* Benefit and disadvantages.
* application.
* Summary.
Overview of advantages and fabrication of solar cells made from silicon nanowires. IT includes few slides of conventional solar cells and benefits of using silicon nanowire.
This presentation summarizes history and recent development of perovskite solar cells. If you have any questions or comments, you can reach me at agassifeng@gmail.com
En esta precentación pueden encontrar el trabajo realizado en el proyecto de lectura en la Escuela Normal Superior Oiba, con el fin de incentivar el gusto lector de los estudiantes del grado segundo uno.
Elysium organize the world’s healthcare information to cure patients reducing errors, time and costs.
This is pitch deck presented to european accelerators in 2016
Atelier de l'UCC Alsace au Club de la Presse de Strasbourg, en septembre 2016, pour aborder les différents axes dans le but de constituer son budget communication en 2017.
This presentation covers following points:-
1. Introduction
2. Introduction to Flexible Solar Cell
3. Flexible Photovoltaic Technology
4. Different types of Flexible Solar Cell
5. Manufacturing Process
6. Testing Method
7. Advantages
8. Applications
9. Conclusion
10. Future Scope
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
3. Research Motivations and Objectives:
Need for an environmentally responsible energy source
• 80% of energy produced from fossil fuels
4. Need for an environmentally responsible energy source
Solar cells are a promising energy technology
• 165,000 terawatts of sunlight
Research Motivations and Objectives:
5. Need for an environmentally responsible energy source
Solar cells are a promising energy technology
Challenge of global implementation
• 500,000 km2 (~ size of Spain)
Research Motivations and Objectives:
6. Need for an environmentally responsible energy source
Solar cells are a promising energy technology
Challenge of global implementation
Use cheap and abundant materials
• Cost prohibiting and Resource prohibiting
• Silver currently used as front contact material
Research Motivations and Objectives:
7. Need for an environmentally responsible energy source
Solar cells are a promising energy technology
Challenge of global implementation
Use cheap and abundant materials
• Cost prohibiting
• Resource prohibiting
Research Motivations and Objectives:
Our lab’s objective
• Replace silver with aluminum
9. P-type Si
N-type Si
Rear Contact (Aluminum)
Solar Cell Basics: Basic Solar Cell Structure
• Simplest functional silicon (Si) solar cell
• 4 Parts: n-type Si, p-type Si, 2 electrodes
Front Contact (Silver)
10. P-type Si
N-type Si
Rear Contact (Aluminum)
Solar Cell Basics: Basic Solar Cell Structure
• Simplest functional silicon (Si) solar cell
• 4 Parts: n-type Si, p-type Si, 2 electrodes
Front Contact (Silver)
11. P-type Si
N-type Si
Rear Contact (Aluminum)
Solar Cell Basics: Basic Solar Cell Structure
• p-n junction formed at boundary
• Permanent electric field formed
Front Contact (Silver)
Electric
Field
12. P-type Si
N-type Si
Solar Cell Basics: Interaction With Sunlight
• Photons absorbed—electron-hole pairs created
• Charges separated by p-n junction
• Charge separation induces current
Electric
Field
14. Solar Cell Fabrication and Structure:
• Our cell’s structure is similar to the model cell
• 2 additional features
Front Contacts
Ni
Al
SiNx Passivation and
ARC Layer
Ag
15. Solar Cell Fabrication and Structure:
Silicon Substrate
P-type Silicon
N-type Silicon
• P-type silicon wafer (200 microns)
• N-type layer made by diffusing phosphorus (0.5 microns)
Phosphorus Diffusion
Rear Al Screen Printing
SiNx Patterning
Ni Sputtering
Front Al Electroplating
SiNx Deposition
16. Solar Cell Fabrication and Structure:
SiNx PassivationandAnti-ReflectionCoating
P-type Silicon
N-type Silicon
• Applied by PECVD (75 nm)
• Passivation effect:
• Minimizes surface recombination
• Anti-reflection coating
SiNx Passivation and
ARC Layer
Phosphorus Diffusion
Rear Al Screen Printing
SiNx Patterning
Ni Sputtering
Front Al Electroplating
SiNx Deposition
17. Solar Cell Fabrication and Structure:
Aluminum Back Contact
P-type Silicon
N-type Silicon
• Screen printed aluminum (10 microns)
Rear Contact (Aluminum)
Phosphorus Diffusion
Rear Al Screen Printing
SiNx Patterning
Ni Sputtering
Front Al Electroplating
SiNx Deposition
18. Solar Cell Fabrication and Structure:
Nickel Seed Layer
P-type Silicon
N-type Silicon
• SiNx etched into front finger pattern
• Nickel layer applied (250 nm)
• Helps adhesion of aluminum
SiNx Passivation and
ARC LayerNi
Rear Contact (Aluminum)
Rear Al Screen Printing
SiNx Patterning
Ni Sputtering
Front Al Electroplating
SiNx Deposition
Phosphorus Diffusion
19. Solar Cell Fabrication and Structure:
Aluminum Front Contact
P-type Silicon
N-type Silicon
• Aluminum electroplated onto nickel
Ni
Al
Rear Contact (Aluminum)
Phosphorus Diffusion
Rear Al Screen Printing
SiNx Patterning
Ni Sputtering
Front Al Electroplating
SiNx Deposition
SiNx Passivation and
ARC Layer
21. Parameter Descriptions:
First, we need to define some parameters
• Efficiency
• Ratio of energy extracted to energy input
• Short-circuit current (JSC):
• Upper-limit to actual current
• Open-circuit voltage (VOC):
• Upper-limit to actual voltage
• Series resistance (RSeries):
• Shunt resistance (RShunt):
23. Parameter Descriptions: RShunt
• RShunt : Resistance to current flow around device
• Example: Current leaking around edges of device, not
through p-n junction
25. PV Cell Performance:Parameter Summary
• Data for another group’s cell was obtained
• Crucial difference is the front electrode material
Ni
Al
Silver
Our groups device Reference cell
28. PV Cell Performance:Parameter Summary
• The current and voltages of both cells are reasonably
close
Our Lab’s
Cell
Reference
Cell
Percent
Difference
Efficiency [%] 12.4 16.8 35
JSC [mA/cm2] 31.8 35.5 12
VOC [V] 0.60 0.61 2
RShunt [Ω-cm2] 183 808 342
RSeries [mΩ-cm2] 1030 393 62
29. PV Cell Performance:Parameter Summary
• The reference cell has a much better RShunt and RSeries
• Poor resistances might account for bad efficiency
Our Lab’s
Cell
Reference
Cell
Percent
Difference
Efficiency [%] 12.4 16.8 35
JSC [mA/cm2] 31.8 35.5 12
VOC [V] 0.60 0.61 2
RShunt [Ω-cm2] 183 808 342
RSeries [mΩ-cm2] 1030 393 62
30. PV Cell Performance:Parameter Summary:
Causes of Poor Resistances
• RShunt:
• Small wafer area
• Contamination
• RSeries:
• Nickel-Silicon and/or Aluminum-Nickel interfaces
• Problems with electroplating
31. Conclusion: Future Work
• Fixing fabrication errors
• Cell area
• Contamination
• Etc.
• Optimizing cell specifications
• SiNx thickness, front contact width/spacing,
electroplating conditions, etc.
32. Conclusion: Project Summary
Goal:
• Demonstrate solar cell with an aluminum front
contact electrode
Results:
• Device performed poorly compared to a similar
reference solar cell
Conclusion:
• Solar cell needs to be improved by optimizing
fabrication and device specifications
33. Questions?
• Study’s objective
• General solar cell operation
• Our groups device or fabrication
• Significance of results
• Miscellaneous
National Science Foundation,
Grant No. ECCS-0335765
Editor's Notes
*Over the course ________ I assisted my lab, under the direction
*First I want to introduce the problem ____ this project is focusing on _____ and how our research fits into the context of this problem
*Energy crisis and energy
*Fossil fuels provide most of the energy
*Need clean energy
*Solar is most promising
*energy factoid
*Collecting even a small fraction is huge challenge
*Spain factoid
*For this to be possible we must only
*Currently one of the more expensive materials used in photovoltaics
*Therefore, our labs goal
*Now I’ll introduce the basic structure and function of photovoltaic devices
REMEMBER TO TALK SLOWER
*Before I move on ______
*Now I’m going to briefly describe the fabrication procedure of our labs device
*Our Device is also simple
*Two additional structures
*Started with p-type
*Diffused phosphorus to make n-type
*Explain shunt resistance
*Large is good
*I found data for cell with structure similar to ours
*Key difference is in front electrode material
*Can compare data between cells to see how performance differ
*Introduce extra columns
*Shunt and series resistance for the reference cell are much better (especially shunt)
*Insinuates that resistances are keeping efficiency down
*Small wafer area: area hit by sunlight too close to edge, therefore, current leak
*Contamination due to shared facilities
*Contact resistance of the…
*We also suspect that the aluminum thickness
*General future goal is to improve cell
*Identifying and eliminating….
*Also, the group will have to play around with cell spec…..
