How solar panels work

3 polymer multilayer modified electrode solar cells replacing inorganic materials with polymers in Solar Cells research direction. The principle is that Multilayer Composite is performed on the surface of conductive material (electrode) by using different redox potentials of different Oxidized-reduced polymers, A one-way conductive device similar to inorganic P - n . The inner layer of one electrode is modified by a polymer with low reduction potential. The reduction potential of the outer polymer is high, and the electron transfer direction can only be transferred from the inner layer to the outer layer. The modification of the other electrode is the opposite, the reduction potential of the two polymers on the first electrode is higher than that of the two polymers in the latter. When two modified electrodes are placed in an electrolytic wave containing a light-sensitivity agent. the electrons produced by the light sensitivity agent after absorption are transferred to the electrode with a low reduction potential. The electrons accumulated on the electrode with a low reduction potential cannot be transferred to the outer polymer, only the external circuit can return to the electrolyte through the electrode with a higher reduction potential, so there is photocurrent in the external circuit. due to the advantages of flexible organic materials, easy production, wide material sources, and low cost, it is of great significance for large-scale use of solar energy and the provision of cheap electricity. However, the preparation of solar cells with organic materials was just beginning, and neither life nor battery efficiency can be compared with inorganic materials, especially silicon cells. Whether it can develop into a product of practical significance remains to be further studied and explored.

4 nano-crystalline chemical solar cells in solar cells, the silicon solar cells are undoubtedly the most mature, but due to high costs, far from meeting the requirements of large-scale application promotion. To this end, people have been constantly exploring technology, new materials, and battery film, the recently developed nano TiO2 crystal chemical energy solar cells have received the attention of scientists at home and abroad. since Professor gratzel developed nano TiO2 chemical dayeneng battery in Switzerland, some units in China are also conducting research in this area. Nano-crystalline chemical solar cells ( NPC batteries) are formed by modifying and assembling the band gap semiconductor material into another kind of high gap semiconductor material, the narrow band gap semiconductor material uses organic compounds such as transition metal Ru and OS as sensitized dyes, the large gap semiconductor material is nano polycrystalline TiO2 and made into an electrode. In addition, the NPC battery also selects an appropriate oxide-reduction electrolyte. Working principle of TiO2 : dye molecules absorb solar energy and transition to the excited state. The excited state is unstable, the electrons are quickly injected into the adjacent TiO2 Guide tape, and the lost electrons in the dyes are quickly compensated from the electrolyte, enter the power in the Guide band of TiO2, and finally enter the Conductive Film . the light current is generated through the external circuit. the advantages of TiO2 crystalline solar cells are their low cost, simple process, and stable performance. The photoelectric efficiency is more than 10 %, and the production cost is only 1/5 ~ of the silicon solar cell ~ 1/10 . The service life can reach 2o years or more. However, as the research and development of such batteries have just started, it is estimated that they will gradually enter the market in the near future.

5 Development Trend of solar cells from the above discussions, we can see that as a material for solar cells, III-V family compounds and CIS are prepared by rare elements, although the conversion efficiency of solar cells made of them is high, however, from the perspective of material sources, such solar cells will not be dominant in the future. The other two types of batteries, nano-crystalline solar cells and polymer modified electrodes, have some problems. Their research is just starting, the technology is not very mature, and the conversion efficiency is relatively low, these two types of batteries are still in the exploratory stage and cannot replace their solar cells within a short period of time. Therefore, from the perspective of conversion efficiency and material sources, the focus of future development is still silicon solar cells, especially polysilicon and amorphous silicon thin film batteries. Due to the high conversion efficiency and relatively low cost of polysilicon and amorphous silicon thin film batteries, they will eventually replace the single crystal silicon battery and become the dominant product in the market. increasing the conversion efficiency and reducing the cost are two main factors in the preparation of solar cells. It is difficult to further improve the conversion efficiency for current solar cells. Therefore, the focus of future research should be on how to reduce costs in addition to continuing to develop new battery materials. The existing high conversion efficiency solar cells are made on high-quality silicon wafers, this is the most expensive part of the manufacturing of silicon solar cells. Therefore, it is particularly important to reduce the cost of the substrate when the conversion efficiency is still high. It is also an urgent problem in the future development of solar cells. Recently, some foreign technologies have used silicon strip as the substrate for polysilicon thin film solar cells to reduce costs.