Introduction of Solar Panels
Introduction of Solar Panels
1. As we all know, solar energy is the most important basic energy source in renewable energy and clean energy, and many countries around the world are studying the conversion and utilization of solar energy. The conversion of solar energy into heat energy by conversion device belongs to solar thermal utilization technology, and the use of heat energy for power generation is called solar thermal power generation; The use of solar energy into electrical energy belongs to solar power generation technology, which is usually converted by the photovoltaic effect (that is, photovoltaic effect) of semiconductor devices, so it is also called solar photovoltaic technology, and the device that converts solar energy into electrical energy is called solar panels or photovoltaic panels.
2. To know how solar panels convert solar energy into electricity, I first need to understand what a P-N junction is. The semiconductor material used to make solar panels is a special substance between conductors and insulators, semiconductor atoms are composed of positively charged nuclei and negatively charged electrons, and the outer layer of semiconductor silicon atoms has 4 electrons, rotating around the nucleus according to a fixed track. When subjected to extraneous energy, these electrons deorbit and become free electrons, leaving a "hole" in their original position. In pure silicon crystals, the number of free electrons and holes is equal. If a silicon crystal is doped with boron, gallium and other elements that can trap electrons, it becomes a hole-type semiconductor, usually denoted by the symbol "p"; If elements such as phosphorus and arsenic are incorporated that can release electrons, it becomes an electronic semiconductor, represented by the symbol "N". If these two semiconductors are combined, their interface forms a P-N junction.
P-N section in the photovoltaic effect
So, how do solar panels convert solar energy into electricity?
The P-N junction is like a wall that blocks the movement of electrons and holes. When the solar panel is exposed to sunlight, the electrons receive light energy and move towards the N-type region, making the N-type region negatively charged, while the holes move to the P-type region, making the P-type region positively charged. In this way, a voltage is generated across the P-N junction. This phenomenon is the above-mentioned "photovoltaic effect". If at this time it is in the P-type layer and the N-type layer respectively
Solder the metal wire, turn on the load, and then the external circuit has current through it. In this way, a certain voltage and current can be generated, that is, the output power can be generated to convert solar energy into electricity. There are more than a dozen known semiconductor materials for manufacturing solar panels, and the technology is currently the most mature