The conversion of the solar cancellation in an electron current happens in the photovoltaic cell, a device constituted from a thin slice of material semiconductor, a lot often silicon, opportunely dealt.
Such treatment is characterized from various chemical processes, between which the “drogaggi” are had the so-called. Inserting in the crystalline structure of the silicon of the impurities, that is boron atoms and phosphorus, an electric field is generated and the necessary charges to the formation of the electric current are made available also. This is created when the cell, whose two faces are connected to an user, is exposed to the light. The energy that can then be taken advantage of depends from the characteristics of the material of which the cell is constituted: the conversion efficiency (percentage of contained energy in the solar cancellations that come transformed in electric power available to the clips) for cells trades them to the silicon generally is comprised between 23% and 30%, while special realizations of laboratory have caught up values of 43.5%. Visit this page to learn how to build solar panels for your home.

How Solar Cell Works

Practically the typical photovoltaic cell has a comprised total thickness between 0,30 and 0,40 milimeter and is constituted from multicrystalline silicon mono or.It, generally of square form, measure usually 125×125 milimeter and produces, with a radiation of 1 kW/mq to a temperature of 27°C, a current comprised between the 3 and the 4 To and a tension of approximately 0,5 V, with one power correspondent of 1,5 – 2 Wp. Since the power of a varied photovoltaic cell to varying of its temperature and the cancellation, for being able to make of the comparisons has been defined of the conditions standard to which ago reference the so-called watt of peak (Wp), relative to the power supplied from the cell to the temperature of 26°C under a cancellation of 1,000 W/mq and in conditions of AM1,5.You can insight more on how solar cell works Already it has been remembered that the photovoltaic cell is substantially a diode valve of great surface. Exposing it to the solar cancellation, the cell is behaved like a current generator, whose operation can be described for means of the characteristic tension-current:Diagram of the course of the characteristic electrical worker according to the temperature (a) and of the solar cancellation. In general terms the characteristic of variable a photovoltaic cell is function of three fundamental ones: intensity of the solar cancellation, temperature and area of the cell.The intensity of the solar cancellation does not have a meaningful effect on the value of the tension to empty; viceversa the intensity of the varied current short-circuit in way proporziona them to varying of the intensity of the radiation, growing to growing of this.The temperature short-circuit does not have a meaningful effect on the value of the current; on the contrary, a relation of proportionality between this exists and the tension to empty, diminishing the tension to growing of the temperature.

The area of the cell does not have some effect on the value of the tension; viceversa a directed proportionality between this exists and the current available. In conditions short-circuit the generated current is maximum (Isc), while in conditions of open circuit the tension (Voc is maximum). In conditions of open circuit and short-circuit the extractable power will be null, since in the relation P = V x I will be null the current in the first case and the tension in the second. In the other points of the characteristic to increasing of the tension it repentinamente increases to the power, catching up therefore a maximum and diminishing in proximity of the Voc. Besides the silicon of crystalline type, lately famous a strong interest, from various companies manufacturers, to realize production lines of modules based on the amorphous silicon (solar paddles to Film Sottile or Thin Film).
With the amorphous one, in reality, draft of depositions of silicon (to the amorphous state cannot be spoken exactly about cells, as) on superficial that can also be wide. The amorphous silicon is present on the market already from various years, but a meaningful market share had till now not been earned, above all because of the existing doubts on its stability in the time since, with passing of the years, often a reduction of the performances was taken place. For this reason the amorphous one came (and comes still today) used above all for applications “indoor”, that is for feeding little ones users, like pocket calculators, clocks, gadget several…

Of recent a productive technology has been put to point that realizes more layers than amorphous silicon, the so-called “eterogiunzione”, that it seems to resolve the past stability problems.
Regarding the cost, the traditional amorphous silicon introduces smaller costs regarding the crystalline silicon (mono or fines), while the amorphous one to two or three splices needs of ulterior reductions of cost so that it can be diffused on wide scale. You can find out more information at Photovoltaics Cell at Wikipedia. The processes of production of the photovoltaic cells are various according to the type of cell that s’intende to realize. The greater differences are had in the formation of the silicon slice, called “wafer”, that it is the main structure on which they will come executed various treatments, especially of chemical nature, that they will carry to the creation of the real cell. The wafer of monocrystal it is produced with the Czochralsky method, based on the crystallization that is originated dipping a “seed” of material much pure one in the liquid silicon; it comes then extracted and cooled slowly in order to obtain a “ingot” of monocrystal, that it will have cylindrical form (from 15 to 34 cm of diameter and 0.20 M of length). The ingot will come drugged having P by means of the boron addition and then mannered in wafer a thickness comprised between the 225 and 325 micrometers.

The wafer of multicrystal it is originated instead from the fusion and successive recrystallization of the refuse silicon of the silicon industry electronic (“scraps”, as it happens also for the wafer of monocrystal).
From this fusion a “bread” is obtained that comes cut vertically in lingotti with form of parallelepipedo.
A successive horizontal cut door to the creation of having slices a thickness similar to that one of the cells of monocrystal (225 – 325 micrometers).

Production of Solar Cell in Solar Panels For Your Home

Regarding the monocrystal, the wafer of multicrystal it concurs interesting efficiencies however with inferior costs. Because the wafer it becomes a real photovoltaic cell, it is necessary (or for the mono that for the multicrystal, first is to clean up it by means of an attack in hard, second is to introduce in the material phosphorus atoms (is the drogaggio of type N), so that the “splice is come true p-n”. This happens making to inside pass slowly the slices of a furnace, that “it diffuses” in material orthophosphoric acid, containing exactly the wished phosphorus atoms. Thirdly, after to have applied to a thin layer of antiglare (titanium dioxide, TiO2), they are come true, for serigrafia or electrodeposition, the contacts front electrical workers (a metallic grill that will collect the electric charges) and posterior (a continuous surface, always metallic) Another one is to this point the cell comes “head” by means of a simulation of the conditions standard of insolation (1000 W/mq to 26~27°C with phantom AM1.5), for being able to classify it and therefore to group with to having cells analogous characteristics electrical workers. This passage is a lot important in order to avoid to realize from each other of the modules with various cells much, that they would carry to a drastic reduction of the performances of the photovoltaic module.

Filed under: Renewable Energy • Solar Cells • Solar Energy • Solar Panel

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