Polycrystalline Polycrystalline Solar Cells is an inexhaustible renewable energy for human beings. But also clean energy, do not produce any environmental pollution. In the effective use of Polycrystalline Polycrystalline Solar Cells, the use of Polycrystalline Polycrystalline Solar Cells in recent years is the fastest growing, most dynamic research areas, is one of the most watched projects.
Polycrystalline Polycrystalline Solar Cells is a radiant energy that must be converted into electricity by means of an energy converter. The energy converter that converts Polycrystalline Polycrystalline Solar Cells (or other light) into electricity is called a solar cell.
The working principle of Polycrystalline Solar Cells is based on the "picnic" effect of semiconductor p-n junctions. The so-called photovoltaic effect, simply put, when the object is subject to light, the body of the charge distribution of the state changes in the resulting electromotive force and current of an effect.
When the solar or other light irradiation of the semiconductor PN junction, the generation of electron-hole pairs, in the vicinity of the semiconductor PN junction generated within the carrier is not compounded to reach the space charge area, attracted by the internal electric field, Area, holes flow into the p region, the results of the n area to store excess electrons, p area has excess holes. They form near the p-n junction with the opposite direction of the potential of the photovoltaic field.
In addition to partially offset the potential of the electric field, the p-zone is positively charged, the n-zone is negatively charged, and the thin layer between the n-region and the p-zone generates the electromotive force, which is the photovoltaic effect. When the energy is added to pure silicon (such as in the form of heat), it causes several electrons to deviate from their covalent bonds and leave the atoms.
Every time an electron leaves, it leaves a hole. Then, these electrons will wander around the lattice, looking for another hole to shelter. These electrons are called free carriers, and they can carry current.
This electric field is equivalent to a diode that allows (or even pushes) electrons from the p-side to the n-side rather than the opposite. When the light in the form of photons hit the Polycrystalline Solar Cells, the energy will release the electronic hole pairs. Each photon carrying enough energy usually releases an electron, resulting in a free hole.
If this occurs in a position close enough to the electric field, or if free electrons and free holes are within its range of influence, the electric field will send electrons to the N side and the holes to the P side. This leads to further neutralization of the electrical neutrality. If we provide an external current path, the electrons pass through the path to their original side (P side), where they are merged with the holes sent by the electric field and flow in the process In doing work. Thereby forming a current from the N-type region to the P-type region. And then form a potential difference in the PN junction, which formed a power supply.
In addition the silicon surface is very bright, will reflect a lot of sunlight, can not be used by the battery. To this end, scientists have applied it with a layer of reflection coefficient is very small protective film, the reflection loss reduced to 5% or less. A battery can provide the current and voltage, after all, limited, so people will be a lot of batteries in parallel or in series to use, the formation of solar photovoltaic panels.
Solar cell power generation is based on the specific material of the photoelectric properties made. Black (such as the sun) radiation of different wavelengths (corresponding to different frequencies) of electromagnetic waves, such as infrared, ultraviolet, visible light and so on. When these rays are irradiated on different conductors or semiconductors, the photon acts as a free electron in the conductor or in the semiconductor.
Polycrystalline silicon direction is better, can be multi-directional to accept the light. We can make a simple experiment: with a hand to block the sun to the solar panel to leave a shadow, so we will be very easy to find the polysilicon to reduce the power generation is not very obvious, and monocrystalline silicon power generation The amount of current is reduced is quite obvious.
Polycrystalline solar panels with the battery, the sun shines on the solar cell plate current generated by the inverter controller to charge the battery, the battery through the inverter controller into a DC or AC for electrical (load) use, or through Grid-connected inverter directly into the power grid. Solar photovoltaic system consists of Polycrystalline Solar Cells (group), solar controller, battery (group), such as the output power for the AC 220V or 110V also need to configure the inverter.
There are two methods of industrialized black silicon velvet technology on the surface of polycrystalline silicon wafers: wet velvet and dry velvet. (MCCE) technology utilizes the Ag / Ag + system energy in AgNO3 to be much lower than the valence band of silicon, so that Ag + obtains valence electrons of silicon and accelerates the reaction with silicon by the H2O2 / HF etching process, The system can corrode nanosized suede on the surface of silicon wafer.