A Close Look
Amorphous silicon does not have the structural uniformity of single or multicrystalline silicon .Small deviations in this material result in defects such as"dangling bonds",where atoms lack a neighbor to which they can bond.These defects provide places for electrons to recombine with holes,rather than contributing to the electrical circuit.Ordinarily,this kind of material would be unacceptable for electronic devices,because defects limit the flow of current.But amorphous silicon can be deposied so that it contains a small amount of hydrogen,in a process called "hydrogenation." The result is that the hydrogen atoms combine chemicaly with many of the dangling bonds,essentially removing them and permitting electrons to move through the materials.
Staebler -Wronski Effect
Instability is the greatest stumbling block for amorphous silicon.These cells experience the stabler-wronski effect,where their electrical output decreases over a period of time when first exposed tho sunlight .Eventally ,however,the electrical output stabilizes.This effect can result in up to a 20% loss in output before the material stabilizes.Exactly why this effect occurs is not fully understood,but part of the reason is likely related to the amorphous hydrogenated nature of the material,one way to mitigate-though not eliminate -this effect is to make amorphous silicon cells that have a multijunction design(discussed in another section).
Cell design
Because of amorphous silicon unique properies,solar cells are designed to have an ultrathin(0.008 micrometer)p-type top layer,a thicker(0.5 to 4 micrometer)intrinsic middle layer,and a very thin (0.02 micrometer)n-type bottom layer .This design is called a "p-i-n"structer,being named for the typed of the three layers.The top layer is made so thin and relatively transparent that most light passes right through it,to generate free electrons is the intrinsic layer.The p-and n-layers produced by doping the amorphous silicon create an electric field across the entire intrinsic region,thus inducing electron movement in that i-layer.
2009年4月11日星期六
Amorphous Silicon
Amorphous Silicon
Amorphous Solids ,like common glass, are materials whose atom are not arranged in any particular order.They don't form crystalline structures at all, and they contain large numbers of structural and bonding defects,but they have some economic advantages over other materials that make them appealing for use in solar electric, or photovoltaic(PV)systems.
In 1974,reseachers began to realize that they could use amorphous silicon in PV devices by properly controlling the condition under which it is deposited and by carefully modifying its composition.Today,amorphous silicon is common is solar-powered consumer devices that have lower power requirments, such as wristwatches and calculators.
Amorphous silicon absorbs solar radiation 40times more efficiently than does single-crystal silicon,so a film only about 1 micrometer or one one-millionth of a meter-thick can absorb 90% .of the usable light energy shinning on it.This is one of the chief reason that amorphous silicon could reduce the cost of photovoltaics.other economic advantage are that it can be produced at lower temperatures and can be deposied on low-cost substrates such as plastic,glass,and metal.This makes amorphous silicon ideal for building-intergrated PV Products like the one shown in the photo.And these characteristics make amorphous silicon the leading thin film pv material.
Amorphous Solids ,like common glass, are materials whose atom are not arranged in any particular order.They don't form crystalline structures at all, and they contain large numbers of structural and bonding defects,but they have some economic advantages over other materials that make them appealing for use in solar electric, or photovoltaic(PV)systems.
In 1974,reseachers began to realize that they could use amorphous silicon in PV devices by properly controlling the condition under which it is deposited and by carefully modifying its composition.Today,amorphous silicon is common is solar-powered consumer devices that have lower power requirments, such as wristwatches and calculators.
Amorphous silicon absorbs solar radiation 40times more efficiently than does single-crystal silicon,so a film only about 1 micrometer or one one-millionth of a meter-thick can absorb 90% .of the usable light energy shinning on it.This is one of the chief reason that amorphous silicon could reduce the cost of photovoltaics.other economic advantage are that it can be produced at lower temperatures and can be deposied on low-cost substrates such as plastic,glass,and metal.This makes amorphous silicon ideal for building-intergrated PV Products like the one shown in the photo.And these characteristics make amorphous silicon the leading thin film pv material.
2009年4月10日星期五
Ribbon Silicon
Ribbon Silicon
Although single-crystal silicon technology is well developed,the Czochralski and float-zone processes are complex and expensive (as are the ingot -casing processed discussed under multicrystalline silicon)Another group of crystal-producing processed,however ,goes by the general name of "ribbon growth" .The single crystal may cost less than other processes, because thy form the silicon directly into thin,usable wafers of single-crystal silicon.these methods involve forming .Thin crystalline sheets directly,thus avoiding the slicing step required of cylindrical rods.
One"ribbon growth"technique-edge-defined film-fed growth starts with two crystal seeds that grow and capture a sheet of meterials between them as they are pulled from a source of moltem silicon.A frame entrains a thin sheet of material when drawn from a melt .This technique does not waste much material,but the quality of the material is not as high as Cz and Fz silicon.
Mulyicrystalline Silicon
Multicrystalline Silicon devices are generally less efficient than those of single-crystal silicon,but they can be less expensive to produce .The multicrystalline silicon can be produced in variety of ways.The most popular commercial methods involve a casting process in which molten silicon is directly cast into a mold and allowed to solidify into an ingot.The starting material can be a refined lower-grade silicon,rether that the higher grade semiconductor grade required for single-crystal material .The cooling rate is one factor that determines the final size of crystals in the ingot and the distribution of impurities.The mold is usually square,producing an ingot that can be cut and sliced into square cells that fit more compactly into a pv module .(Round cells have spaces between them in modules ,but square cells fit together better with a minimum of wasted space)
Although single-crystal silicon technology is well developed,the Czochralski and float-zone processes are complex and expensive (as are the ingot -casing processed discussed under multicrystalline silicon)Another group of crystal-producing processed,however ,goes by the general name of "ribbon growth" .The single crystal may cost less than other processes, because thy form the silicon directly into thin,usable wafers of single-crystal silicon.these methods involve forming .Thin crystalline sheets directly,thus avoiding the slicing step required of cylindrical rods.
One"ribbon growth"technique-edge-defined film-fed growth starts with two crystal seeds that grow and capture a sheet of meterials between them as they are pulled from a source of moltem silicon.A frame entrains a thin sheet of material when drawn from a melt .This technique does not waste much material,but the quality of the material is not as high as Cz and Fz silicon.
Mulyicrystalline Silicon
Multicrystalline Silicon devices are generally less efficient than those of single-crystal silicon,but they can be less expensive to produce .The multicrystalline silicon can be produced in variety of ways.The most popular commercial methods involve a casting process in which molten silicon is directly cast into a mold and allowed to solidify into an ingot.The starting material can be a refined lower-grade silicon,rether that the higher grade semiconductor grade required for single-crystal material .The cooling rate is one factor that determines the final size of crystals in the ingot and the distribution of impurities.The mold is usually square,producing an ingot that can be cut and sliced into square cells that fit more compactly into a pv module .(Round cells have spaces between them in modules ,but square cells fit together better with a minimum of wasted space)
Single-crystal Silicon
Single-Crystal Silicon
To creat a silicon in a single-crystal state,we must first melt high-purity silicon.we then cause it to reform or solidify very slowly in contact with a single crystal"seed" the silicon adapts to the pattern of the single-crystal seed as it cools and gradually solidifies.Not surprisingly,because we start form a seed,we say this process is "growing"a new rod (often called a "boule") of single-crystal silicon out of molten silicon.Several different processes can be used to grow a boule of singly-crystal silicon .The most established and dependable processes are the Czochralski (Cz) method and the float-zone(Fz)techique .we also discuss"ribbon-growth" techniques.
Czochralski Silicon
In the Czochralski process, a seed crystal is dipped into a crucible of molten silicon and withdrawn slowly,pulling a cylindrical single crystal as the silicon crystallines on the seed.
Float-zone Silicon
The float-zone process produces purer crystals than the Czochralski method, because they are not contaminated by the crucible used in growing Czochralski crystal .In the float-zone process , a silicon rod is set atop a seed crystal and then field induces an electric field in the rod .Heating and melting the inerface between the rod and the seed.Single-crystal silicon forms at the interface.Growing upward as the coils are slowly raised.
Once the single-crystal rods are produces ,by either the Cz or Fz method, they must be sliced or sawn to form this wafers.Such sawing ,however ,wasters as much as 20% of the valuable silicon as sawdust ,known as"kerf" .The resulting thin wafers are then doped to produce the necessary electric field .They are then treated with a coating to reduce reflection, and coated with electrical contacts to form functioning Pv Cells.
To creat a silicon in a single-crystal state,we must first melt high-purity silicon.we then cause it to reform or solidify very slowly in contact with a single crystal"seed" the silicon adapts to the pattern of the single-crystal seed as it cools and gradually solidifies.Not surprisingly,because we start form a seed,we say this process is "growing"a new rod (often called a "boule") of single-crystal silicon out of molten silicon.Several different processes can be used to grow a boule of singly-crystal silicon .The most established and dependable processes are the Czochralski (Cz) method and the float-zone(Fz)techique .we also discuss"ribbon-growth" techniques.
Czochralski Silicon
In the Czochralski process, a seed crystal is dipped into a crucible of molten silicon and withdrawn slowly,pulling a cylindrical single crystal as the silicon crystallines on the seed.
Float-zone Silicon
The float-zone process produces purer crystals than the Czochralski method, because they are not contaminated by the crucible used in growing Czochralski crystal .In the float-zone process , a silicon rod is set atop a seed crystal and then field induces an electric field in the rod .Heating and melting the inerface between the rod and the seed.Single-crystal silicon forms at the interface.Growing upward as the coils are slowly raised.
Once the single-crystal rods are produces ,by either the Cz or Fz method, they must be sliced or sawn to form this wafers.Such sawing ,however ,wasters as much as 20% of the valuable silicon as sawdust ,known as"kerf" .The resulting thin wafers are then doped to produce the necessary electric field .They are then treated with a coating to reduce reflection, and coated with electrical contacts to form functioning Pv Cells.
Silicon
Silicon used to make some the earliest photovoltaic(PV)decices is still the most popular material for solar cells.Outranked only by oxygen,silicon is also the second-most abundant element in the earth's cust.However ,to be useful as a semiconductor material in solar cells,silicon must be refined to a purity of 99.9999%
In single-crystal silicon ,the molecular structure-which is the arrangement of atoms in the material is uniform,because the entire stucture is grown from the same crystal.This uniformity is ideal for transferring electrons effciently through the material .To make an effective Pv cell, however ,silicon has to be “doped” with other elements to make it n-type and p-type.
Simicrystalline silicon ,in contrast,consist of several smaller crystals or grains ,which introduce boundaries.These boundarias impede the flow of electrons and encourage them to recombine with holes to reduce the power output of the solar cell.However ,semicrystalline silicon is much less expensive to produce than single-crystalline silicon.So researchers are working on other ways to minimize the effects of grain boundaries .
In this section,we will cover silicon solar cell materials in :
Single-crystal silicon
Multicrystalline silicon
Amorphous silicon
In single-crystal silicon ,the molecular structure-which is the arrangement of atoms in the material is uniform,because the entire stucture is grown from the same crystal.This uniformity is ideal for transferring electrons effciently through the material .To make an effective Pv cell, however ,silicon has to be “doped” with other elements to make it n-type and p-type.
Simicrystalline silicon ,in contrast,consist of several smaller crystals or grains ,which introduce boundaries.These boundarias impede the flow of electrons and encourage them to recombine with holes to reduce the power output of the solar cell.However ,semicrystalline silicon is much less expensive to produce than single-crystalline silicon.So researchers are working on other ways to minimize the effects of grain boundaries .
In this section,we will cover silicon solar cell materials in :
Single-crystal silicon
Multicrystalline silicon
Amorphous silicon
DIY Solar Guide
DIY Solar Guide
Welcome to solar shop. Solar cell is high technology product,while it’s easy to install at home. It’s really rewarding after you have installed .It gives us green electricity,bright life,happy future .
What do we need a solar kits for ?
Solar light ,solar security, solar garden light ,solar mobile recharger ….
What are the benefits of installing a solar kit?
Solar electricity is free, energy-saving, money saving, and environmentally friendly!
There are a number of benefits in installing your own solar kit solar kits are cheaper when you install them yourself, we do offer an installation service, if you would prefer us to install your solar panel system for you please call 86-15989515015( Cher zheng )for free advice.
Solar power:
• requires no maintenance (or running costs)
• cuts your electricity bills
• produces electricity in daylight, not just sunlight ,work in cloudy day .
• is kinder to the environment
• is easily integrated with a property
• Increase price of property
• gives you the option of selling surplus electricity
• produces no carbon emissions or pollution
• leaves no waste for future generations
• solar photovoltaic panels are proven technology
• reduces dependence on fossil fuels
• Teach your children the way forward!
• You can also register as an independent energy generator and sell your own electricity to the Gas and Electricity Market Authority.
A photovoltaic (PV) solar energy system installed by Solar Shop will produce many benefits for you and the environment, now and in the future.
Unlike many other Energy providers, once you have installed a PV solar energy system, you will be able to generate electricity for free. The system has no ongoing costs, and because there are no mechanical or moving parts it does not require maintenance.
With a PV solar energy system you will be reducing your dependence on the national grid to fulfil your electricity requirements. The amount of money you will save will depend on how much electricity your household or building uses and how energy-efficient the building and appliances are.
Our photovoltaic panels are among the best available today made up of highly efficient cells that generate electricity even on cloudy days.
Solar systems reduce our requirement for mass installations such as power stations or wind farms and miles of pylons and cables to generate and distribute electricity. By having your own renewable energy source you will be minimising the impact on our landscape and protecting the environment.
Photovoltaic panels generate power without burning any fossil fuels, so by using solar electricity you will be helping to conserve our finite fossil-fuel resources for the current and future generations.
Using sunlight to generate electricity is clean, silent and limitless. It allows you to create power without creating carbon dioxide or other pollutants that contribute to global warming.
As well as being very clean, solar power allows you to generate electricity without leaving harmful waste products that build up to become a problem for us and future generations. Solar power is therefore a proven, reliable and very safe way of producing electricity.
Whether you are designing and constructing a new building or want to retrofit a solar electricity system to an existing building, this type of renewable energy source can be easily incorporated. We can make and design a solar system for you .
As a renewable energy source, photovoltaic panels have been used for some time. They have proved to be reliable and they do work as a way of reducing your reliance on less ‘green’ energy production, and will ultimately save you a large amount of money.
How do Install a solar kit?
Technical helpline 86-15989515015
Email:solarpanelcn@gmail.com
Solar.module@hotmail.com
Cher_zheng@solar-global.cn
MSN: cher_zheng@yahoo.com.cn
Skype: cher_zheng
QQ: 9096785
How does it work?
When light hits the silicon in a solar PV cell, electrical energy is created.
The electricity flows through a cable and is collected at a central point, often located in your roof space.
At this central point the electricity is converted from Direct Current (DC) to Alternating Current (AC) and carries on into your household electricity system.
Contact
Cher Zheng(Ms)
Mobile: 86-15989515015
Email:solarpanelcn@gmail.com
Solar.module@hotmail.com
Cher_zheng@solar-global.cn
MSN: cher_zheng@yahoo.com.cn
Skype: cher_zheng
QQ: 9096785
Welcome to solar shop. Solar cell is high technology product,while it’s easy to install at home. It’s really rewarding after you have installed .It gives us green electricity,bright life,happy future .
What do we need a solar kits for ?
Solar light ,solar security, solar garden light ,solar mobile recharger ….
What are the benefits of installing a solar kit?
Solar electricity is free, energy-saving, money saving, and environmentally friendly!
There are a number of benefits in installing your own solar kit solar kits are cheaper when you install them yourself, we do offer an installation service, if you would prefer us to install your solar panel system for you please call 86-15989515015( Cher zheng )for free advice.
Solar power:
• requires no maintenance (or running costs)
• cuts your electricity bills
• produces electricity in daylight, not just sunlight ,work in cloudy day .
• is kinder to the environment
• is easily integrated with a property
• Increase price of property
• gives you the option of selling surplus electricity
• produces no carbon emissions or pollution
• leaves no waste for future generations
• solar photovoltaic panels are proven technology
• reduces dependence on fossil fuels
• Teach your children the way forward!
• You can also register as an independent energy generator and sell your own electricity to the Gas and Electricity Market Authority.
A photovoltaic (PV) solar energy system installed by Solar Shop will produce many benefits for you and the environment, now and in the future.
Unlike many other Energy providers, once you have installed a PV solar energy system, you will be able to generate electricity for free. The system has no ongoing costs, and because there are no mechanical or moving parts it does not require maintenance.
With a PV solar energy system you will be reducing your dependence on the national grid to fulfil your electricity requirements. The amount of money you will save will depend on how much electricity your household or building uses and how energy-efficient the building and appliances are.
Our photovoltaic panels are among the best available today made up of highly efficient cells that generate electricity even on cloudy days.
Solar systems reduce our requirement for mass installations such as power stations or wind farms and miles of pylons and cables to generate and distribute electricity. By having your own renewable energy source you will be minimising the impact on our landscape and protecting the environment.
Photovoltaic panels generate power without burning any fossil fuels, so by using solar electricity you will be helping to conserve our finite fossil-fuel resources for the current and future generations.
Using sunlight to generate electricity is clean, silent and limitless. It allows you to create power without creating carbon dioxide or other pollutants that contribute to global warming.
As well as being very clean, solar power allows you to generate electricity without leaving harmful waste products that build up to become a problem for us and future generations. Solar power is therefore a proven, reliable and very safe way of producing electricity.
Whether you are designing and constructing a new building or want to retrofit a solar electricity system to an existing building, this type of renewable energy source can be easily incorporated. We can make and design a solar system for you .
As a renewable energy source, photovoltaic panels have been used for some time. They have proved to be reliable and they do work as a way of reducing your reliance on less ‘green’ energy production, and will ultimately save you a large amount of money.
How do Install a solar kit?
Technical helpline 86-15989515015
Email:solarpanelcn@gmail.com
Solar.module@hotmail.com
Cher_zheng@solar-global.cn
MSN: cher_zheng@yahoo.com.cn
Skype: cher_zheng
QQ: 9096785
How does it work?
When light hits the silicon in a solar PV cell, electrical energy is created.
The electricity flows through a cable and is collected at a central point, often located in your roof space.
At this central point the electricity is converted from Direct Current (DC) to Alternating Current (AC) and carries on into your household electricity system.
Contact
Cher Zheng(Ms)
Mobile: 86-15989515015
Email:solarpanelcn@gmail.com
Solar.module@hotmail.com
Cher_zheng@solar-global.cn
MSN: cher_zheng@yahoo.com.cn
Skype: cher_zheng
QQ: 9096785
Home page
Welcome to Solar Shop we are the best priced solar manufactory in China .we have our PECVD and laser processes,don’t worry about supply shortages ,customize different specification for you ,with solar home system, outdoor light, emergency light, mosquito zappers ect.Can always have fresh selection to choose ,contact us today .
contact : Cher zheng
Thanks & Best regards
Cher Zheng(Ms)
MB:86-15989515015
msn:cher_zheng@yahoo.com.cn
yahoo: cher_zheng@yahoo.com.cn
hotmail:solar.module@hotmail.com
skype: cher_zheng
Google talk: solarpanelcn
www.solarglobal.blogspot.com
Shenzhen Global Solar Energy
contact : Cher zheng
Thanks & Best regards
Cher Zheng(Ms)
MB:86-15989515015
msn:cher_zheng@yahoo.com.cn
yahoo: cher_zheng@yahoo.com.cn
hotmail:solar.module@hotmail.com
skype: cher_zheng
Google talk: solarpanelcn
www.solarglobal.blogspot.com
Shenzhen Global Solar Energy
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