Garden Solar Pest Repeller

Garden Solar Pest Repeller

A kind of solar energy device making use of ultrasonic to expel moles.

To expel rodents(applicable to such animals as moles and shrews),operated on solar energy
Thank you for your purchasing Garden Solar Pest Repeller.Transmitting ultrasonic via vibration,Garden solar pest repeller is used to affect the acute hearing of underground rodents,with very effective preventive effect.The ultrasonic will deceive them,making them feel endangered,so so to force them away from the vibrating area.Transmitting ultrasonic every 30 seconds,Garden Solar Pest Repeller has an effective range of 650 square meters.

Garden Solar Pest Repeller Radiates in all directions.Durning Radiation,there shall be no any obstruction to tamper with the ultrasonic .To achieve the best performance,we strongly recommend that 2 devices be installed every 30 meter for those areas frequented by rodents.

Garden Solar Pest Repeller works on a solar cell,while the other rechargeable cell is charged for nocturnal use.When a cell is fully charged .It can supply power when lights to drive Garden Solar Pest Repeller,So as to ensure continuous 48-hour operation.

Parameters:
Dimension: 43cm x 15.5cm x15.5cm
Weight: 360g
Power supply: solar energy cell,or long-effective Ni-Cad cell recharged by solar enegy
Frequency: 400Hz-1000Hz

Matters for attention:
The ground shall be chaecked when getting out the device,frozen earth,irrigated ground or waterlogged ground is forbidden.First ,dig a hole in solid earth to place the device,and the density of earth will greatly affect the effective running of the device.A certain error margin shall be reserved according to the density of the earth will greatly affect the effecticve running of the device.A certain error margin shall be reserved according to the density of the earth prior to measuring the actually effective range.

No hammer shall be used when installing,no excessive force shall be applied,so as to avoid damaging the device.

Installation wizard:
1) Connect the two connectors on the aluminum bar onto the joints on the top,watch out that the colors of the joints shall match: red with red,and black with black (please refer to the following illustration)



2) Fix the bar and the top together
3)Insert the bar into the earth ,be careful not to use execssive force to damage the device,or bump into any obstruction.The base of the top shall be exposed to the outside,about 1cm above the ground.

Multijunction Devices

Multijunction Devices

This structure ,also called a cascade or tandem cell,can achieve a higher total conversion efficiency by capturing a larger portion of the solar spectrum.In the typical multijunction cell,individual cells with different bandgap are stacked on top of one another.The individual cells are stacked in such a way that sunlight falls first on the material having the largest bandgap.Photons not absorbed in the frist cell are transmitted to the second cell,which then absorbs the higher-energy portion of the remaining solar radiation while remaining transparent to the lower-energy photons.These selective absorption processes continue through to the final cell,which has the smallest bandgap.

A multijunction cell can be made in two different ways in the machanical stack approach ,two individual solar cells are made independently,one with a high bandgap and one with a lower bandgap.Then the two cells are machanically stacked,one on top of the other.In the monolithic approach ,one complete solar cell is made first,and then the layers for the second cell are grown or deposited directly on the first.

Much of today's research in multijunction cells focuses on gallium arsenide as one or all of the component cells.These cells have efficient of more than 35% under concentrated sunlight which is high for PV DEVICES.Other materials studied for multijunction devices are amorphous silicon and copper indium diselenide.

P-i-n and n-i-p Devices

P-i-n and n-i-p Devices

Typically amorphous silicon thin-film cells use a p-i-n structure,wheras cdTe cells use an n-i-p structure.The basic scenario is as follows:A three-layer sandwich is created,with a middle intrinsic (i-type or undoped)layer between an n-type layer and a p-type layer.This geometry sets up an electric field between the p-type and n-type regions that stretches across the middle intrinsic resistive region.Light generates free electrons and holes in the intrinsic region,which are then separated by the electric field.

In the p-i-n amorphous silicon(a-si) cell,the top layer is p-type a-si,the middle layer is intrinsic silicon,and the bottom layer is n-type a-si.Amorphous silicon has many atomic-level electrical defects when it is highly conductive .So very little current would flow if an a-si cell had to depend on diffusion.However,in a p-i-n cell,current flows because the free electrons and holes are generated within the influence of an electric field,rather than having to move toward the field.

In a CdTe cell,the device structure is similar to the a-si cell,except the order of layer is flipped upside down.Specifically,is a typical cdTe cell,the top layer is p-type cadmium sulfide (cds),the middle layer is intrinsic cdTe,and the bottom layer is n-type zinc telluride(znTe).

Heterojunction Device

Heterojunction Device

An example of this type of device structure is a CIS cell,where the junction is formed by contacting two different semiconductors Cds and CuInse.This structure is often chosen for producing cells made of thin-film materials that absorb light much better than silicon.The top and bottom layers in heterojunction device have different roles.The top layer,or "window" layer,is a material with a high bandgap selected for its transparency to light.The window allows almost all incident light to reach the bottom layer,wich is a material with low bandgap that readily absorbs light.This light then generates electrons and holes very near the junction, which helps to effectively separate the electrons and holes before they can recombine .

Heterojunction devices have an inherent advantage over homojunction devices,which require materials that can be doped both p- and n- type.Many PV materials can be doped either p-type or n-type,but not both.Again, because heterojunction don't have this constrain,many promising pv materials can be investigated to produce optimal cells.

Also, a high-bandgap window layer reduces the cell's series resistance,the window material can be made highly conductive , and the thickness can ba increased without reducing the transmittance of light.As a result, light-generated electrons can easily flow laterally in the window layer to reach an electrical contact.

From:http://www1.eere.energy.gov/solar/pv_batteries.html

Homojunction Device

Homojunction Device
Crystalline silicon is the primary example of this kind of cell:
A Single material-crystalline silicon is altered so that one side is p-type,dominated by positive holes,and the other side is n-type,dominated by nagative electrons.The p/n junction is located so that the maximuum amount of light is absorbed near it.The free electrons and holes generated by light deep in the silicon deffuse to the p/n junction,then separate to produce a current if the silicon is of sufficient high quality.
In this homojunction design,we may vary several aspects of the cell to increase conversion efficiency:
*Depth of the p/n junction below the cell's surface.
*Amount and distribution of dopant atoms on either side of the p/n junction.
*Crystallinity and purity of the silicon.

Some homojunctions cells have also been designed with the positive and negative electrical contacts on the back of the cells.This geometry eliminates the shadowing caused by the electrical grid on top of the cell.A disadvantage is that the carge carriers,which are mostly generated near the top surface of the cell,must travel farther all the way to the back of the cell to reach on electical contact.To be able to do this,the silicon must be of very high quality,without crystal defects that cause electrons and holes to recombine.



From: http://www1.eere.energy.gov/solar/silicon.html

Solar Cell Structures

Solar Cell Structures
The actual structural design of a photovoltaic device depends on the limitation of the material used in the PV cell.We will look briefly at four basic device designs commonly used with the materials we have discussed.
*Humojunction
*Heterojunction
*P-I-N/N-I-P
*Multijunction

From:http://www1.eere.energy.gov/solar/solar_cell_structures.html

Solar Mobile Recharger

Solar Mobile Recharger

There different kind of solar mobile recharger .

5 Watt Thin-film (A-Si) Solar Panel

5 Watt Thin-film (A-Si) Solar Panel

Description
This 5 watt thin-film solar panel is made from amorphous silicon technology. This solar panel is perfect to charge 12 volt car batteries for any projects of any type. It comes with aluminum stand which sets the solar panel at the perfect angle for optimal power output.

Features
New thin-film solar techhnology (Amorphous silicon)
Aluminium frame with junction box & cable with battery clamps
Aluminum stand for optimal power output
EVA+PETLaminator

Specifications
Dimensions: 15.4 inches x 12.9 inches x .86 inches
Power output: ~5W
Voltage (Vmp): 17-21V
Voltage Open Circuit (Voc): 25-29V
Amperage (Isc): 320-400mA

contact cher zheng to get more information .
MB:86-15989515015
msn:cher_zheng@yahoo.com.cn
hotmail:solar.module@hotmail.com

Solar Cell Materials

Solar Cell Materials


Solar Cells can be made from a wide range of semiconductor materials .in the following sections,we will discuss:
*Silicon(Si) -including single-crystalline Si,multicrystalline Si,and amorphous si.
*Polycrystalline thin films-including copper indium diselenide (cis) ,cadmium telluride(cdTe),and thin-film silicon
*Single-crystalline thin-including high efficiency material such as gallium arsenide(GaAS)
First ,though,we provide an overview of aspects that relate to all materials.This discussion serves as a basis for the more detailed section on individual materials .The aspects we will cover are crystallinity,absortion,bandgap,and complesity of manufacturing.
Crystallinity
The crystallinity of a material indicates how perfectly ordered the atoms are in the crystal structures .Silicon,as well as other solar cell semiconductor materials ,can come in various forms:Single-crystalline,multicrystalline,polycrystalline,or amorphous.In a single-crystal material the atoms making up the framework of the crystal are repeated in a very regular,orderly manner from layer to layer.In contrast, in a material composed of numerous smaler crystals,the orderly arrangement is disrupted.moving from one crystal to another.One classification scheme for silicon uses approximate crystal size and also includes the methods trypically used to grow or deposit such material.

Thype of Silicon Abbreviation Crystal size range Deposition Method
Single-crystal Silicon sc-si >10cm Czochralski,Float zone
Multicrystalline silicon mc-si 1mm-10cm Cast,sheet,ribbon
Polycrystalline Silicon pc-si 1mm-10cm Chemical-vapor deposition
Microcrystalline silicon mc-si <1mm Plasma deposition

Absorbtion
The absorption coefficient of a material indicates how far light having a specific wavelength(or energy) can penetrate the material before being absorb .A samll absorbed by the material .Again ,the absorption coefficient of a solar cell depends on two factors: the material making up the cell, and the wavelength or energy of the light being absorbed.Solar cell material has an abrupt edge in its absorption coefficient.The reason is that light whose energy is below material's bandgap cannot free an electron.And so,it isn't absorbed .

Bandgap
The bandgap of a semiconductor material is an amount of energy.Specifically,it's the minimum energy needed to move an electron from its bound state with an atom to a free state .This free state is where the electron can be involved in conduction .The lower ernergy level of a semiconductor is called the "Valence band " And the higher energy level where an electron is free to roam is called the "conduction band" the bandgap (often symbolized by E9) is the energy difference between the conduction band and valence band .

Complexity of Manufacturing
The most importants parts of a solar cell are the semiconductor layers .Because this is where electrons are are freed and the electric current is created-it's the active layer"where the action is ," so to speak.Several different semiconductor materials are used to make the layers in different types of solar cells.and each material has its benefits and drawbacks.

The most and complexity of manufacturing may vary across these materials and device structures based on many factors,including deposition in a vacuum environment,amount and type of material utilized,number of steps involved,need to move cells into different deposition chambers or processing process,and others.

From: http://www1.eere.energy.gov/solar/solar_cell_materials.html