Solar Secret
The sun is from Earth and the recent burning of a huge planet, its diameter is 1.392 × 106 km, is 109 times Earth's diameter to laptop battery. The quality of the sun for 1.989 × 1027 kg and is 330,000 times the Earth. Center temperature of the sun as much as about 1.2 million degrees Celsius, the pressure as high as 3.4 × 1016 Pa, where the nuclear fusion reaction at a time when, as a huge hydrogen bomb for many in the continuing explosion of the total energy released it as high as 3. 83 × 1020MW. Of these, only 1 / (2.2 × 108) to reach the Earth's atmosphere above. In these the energy reaching the Earth, the 30% reflection back to space by the atmosphere, 23% of atmospheric ibm battery absorption, and only 47% or 8.2 × 1010 MW to reach the Earth's surface.
Outside to remove large quantities of solar energy, but also long-term supply, the theoretical calculation of the sun billions of years can last a few years, in addition, have a solar energy everywhere, without exploitation and transport, and there is no contamination of clean energy. These are its unique features. However, its energy density is very low, only 1W/m2, and by climate instability with, those given the use of solar energy has caused great difficulties. Mankind has been exploring the use of solar energy, solar cells is one way.
Solar photovoltaic effect is a semiconductor device. In 1839, the French physicist A. E. Becquerel accidentally discovered by two metal submerged in the solution, consisting of photovoltaic cells, are produced when sunlight extra PV potential, a phenomenon he called the photovoltaic effect. In 1883, it was in contact with the semiconductor and metal selenium found solid photovoltaic effect. Later, they can produce photovoltaic device known as the photovoltaic effect of the device. Since the PN junction semiconductor device under the sun the highest photoelectric conversion efficiency, and are usually devices such as photovoltaic solar cells, also known as photovoltaic cells or solar cells.
Semiconductor in electronic state of the campaign, according to the energy can be divided into the conduction band and valence band, the energy gap between the two known as the band gap. In the conduction band in the electronics, semiconductors in the entire freedom movement, conduction current. Valence band in the electronics, only movement around the nucleus, not conduction current. Semiconductor by light, heat or other external energy excitation, the valence band of the electronic transitions into the conduction band will be in the valence band leaving a hole. Positively charged hole, but also in the freedom movement in the entire semiconductor, conduction current. Conduction current to the electron and hole known as the carrier. Electron and hole pairs are pairs exist. Produced by electronic excitation, hole of the process, known as the optical excitation.
A typical solar cell structure is a thick 0.2 ~ 0.3 mm, an area of 5 cm × 5 cm or 10 cm × 10 cm sheet of silicon, the upper price is 5 element phosphorus mixed and rely on a large number of electronic conductivity of N-type silicon. The lower part of the trivalent element boron mixed and rely on the hole conductivity of the P-type silicon. Node is just the interface. N-type silicon surface has a thin cloth of the metal gate line, close to the other side of P-type silicon. In order to reduce the reflection, the entire cell surface covered with a layer of transparent antireflection coating.
PN junction solar cells the existence of a point P by the N area of the electric field area. When the sunlight to the solar cell surface, small part is reflected, most through the antireflection coating into the silicon cells, which is greater than the energy band gap of the photon is absorbed by silicon, the photo-excited carrier. In the N area of the photo-generated hole to end the proliferation of PN into the PN junction area, was with the electric field to the P District. P area in the photo-generated electron-proliferation first PN junction and entered the PN junction area, was with the electric field to the N area. Just end zone in the electron hole pair, then immediately to the electric field, respectively, N area and P area. Therefore, solar cells have been irradiated in, N area and accumulated a large number of photo-electronics, and P, while the accumulation of a large number of cavities, in the PN junction on both sides of a photo-electromotive force. If the two electrodes in an indirect load, electrical currents will be light through the load. In this way the sun's light energy directly into electric energy.
China Science and Technology Museum exhibits "solar cell", is an array of solar panels on the wall, with two hands incandescent sun. When viewers press the switch, the "sun" light off, as in the on-board solar cells, solar cells work immediately, the issue of power driven flywheel turning color, and car drivers to walk round triangle.
Soft cloth, such as portable, solar-powered ibm thinkpad t40 battery, ibm thinkpad t40p battery cell phone battery charger for mobile phones at any time
Travel time for mobile phone charging trouble, one way to find the power, and the other is charging on the road need to stay a certain time, travel delays. Now, this problem can be solved, as scientists develop a new generation of solar cells can be recharged while walking, not only can charge mobile phones, but also to the laptop, PDA, and DVD players and even charge the battery. Moreover, such a high-tech solar cells is also more than one. Solar tents of plastic sheeting can be done
Nobel Prize winner from Alan Haig (AlanHeeger) created a new solar company Konarka and Swiss research institutions are working together to develop a plastic sheeting to collect solar energy.
Co-operative research projects of the overall goal is to develop within one year based on photovoltaic solar energy functional fiber plastic sheeting, plastic sheeting can be used to produce such a light inside the tent or be able to charge the phone pants, backpacks, tents and coverage objects.
Joint development of Konarka new material - Optical fiber and quantum dots can capture all of the visible and invisible light, the conversion of light energy into electrical energy, greatly improving the utilization of solar energy. Star-shaped cells can be attached to the clothes
Recently, Gifu University, Japan, invented a solar cell astrocytoma has been the subject of reports, can be attached to clothes, travel clothes with cell phones can charge. This solar cell thickness of 0.4 millimeters, with an area of 4 square centimeters, the power of 5 mW, the shape of five-pointed star. In the production of clothes can be a number of such solar cells arranged in accordance with certain rules, attached to the clothes, and then use a dedicated line connection, clothing can charge a cell phone. Flexible solar cells can be rolled away
A few days ago, European scientists have invented a kind of texture, light and flexible solar cells, can be rolled up, carried out on the rear windows of motor vehicles, the children will be able to charge the DVD can also be sewn on fabric, or buy on the surface to the cell phones and other electrical charge than the previous glass solar panel is much more useful.
The solar cell is a group called the "H-AlphaSolar" the product of the European Union research project, referred to as "H-AS cells", is expected to be listed after three years.
The top solar cell production line set up Jiangning
The afternoon of April 4, major support from the state's new high-tech enterprises in Nanjing Photovoltaic Technology Co., Ltd. CLP, ushered in the first batch of the world's most advanced solar cell production lines. A production line of 30 million U.S. dollars investment planned for completion in June this year. Put into operation, it is expected that annual production value of 1.5 billion, annual profits and taxes 100 million yuan. Yesterday, the factory production line, including solar cells: PECVD coating machine (Germany), vacuum baking furnace node (USA), automatic screen printing production line (Italy) and so on. According to general manager, Australia and Dr. Zhao Jianhua scholars that these devices are at the top level of the world.
Nanjing, China Light and Power was established in photovoltaic technology companies on October 8 last year, is a company engaged in solar cell ibm thinkpad t41 battery, ibm thinkpad t41p battery manufacturing, R & D, sales and technical services to the new high-tech enterprises. Dr. Zhao Jianhua has led a research team in Australia, the design and manufacture of high-performance silicon solar cells, polycrystalline silicon, respectively, single crystal silicon solar cells and photovoltaic conversion rate to 24.7% and 19.8%, for 15 years maintain the highest in the world. This solar-powered battery-powered trams, the maximum charge for a power running 3000 kilometers.
