1. Current status and influencing factors of photoelectric conversion efficiency
Although the current photoelectric conversion efficiency of solar cell modules has reached a certain level, it still faces many limitations. Its conversion efficiency is restricted by the characteristics of semiconductor materials. For example, the band gap width of traditional silicon materials limits the absorption and utilization efficiency of photons of different wavelengths. In addition, the electron recombination process inside the battery will also cause energy loss, including surface recombination and body recombination. The reflection loss of light on the surface of the battery and the resistance loss inside the battery make it impossible for some light energy to be effectively converted into electrical energy. For example, the photoelectric conversion efficiency of crystalline silicon solar cells can reach about 25% under ideal laboratory conditions, but the module efficiency in actual applications will be reduced to 15%-20% due to various losses.
2. Bottleneck analysis under existing technologies
Within the framework of existing technologies, some bottlenecks are difficult to break through. On the one hand, the purity and crystal structure of the material are difficult to further optimize. Even if high-purity silicon materials are used, impurities and defects will still exist to a certain extent and affect electron transmission. On the other hand, the traditional battery structure and manufacturing process limit the full capture and conversion of light energy. For example, conventional planar solar cells have poor absorption effects on oblique incident light, and the series resistance of the cell is difficult to reduce to an ideal level, resulting in heat loss during current transmission. At the same time, existing packaging technology may also affect the incidence of light and the dissipation of heat to a certain extent, indirectly reducing the photoelectric conversion efficiency.
3. Breakthrough path of new material research and development
In order to break through the bottleneck of photoelectric conversion efficiency, new material research and development is one of the key directions. New semiconductor materials such as perovskite materials have adjustable band gap widths and can more effectively absorb photons in the visible light range. In theory, there is a large room for improvement in photoelectric conversion efficiency. Combining perovskite with traditional materials such as silicon to form a stacked cell structure can expand the spectral absorption range and reduce energy loss. In addition, quantum dot materials have also attracted much attention. Their size effect can accurately control the band gap. By rationally designing the composition and size of quantum dots, it is expected to improve the absorption and conversion efficiency of photons of specific wavelengths, opening up new ways to improve the efficiency of solar cell modules.
4. Breakthrough path of structural and process innovation
Structural and process innovation are equally important. The use of micro-nanostructured battery surface design, such as nanotexture, anti-reflective coating, etc., can effectively reduce light reflection, increase light absorption paths, and improve light capture efficiency. In the internal structure of the battery, optimize the electrode design and carrier transmission channel, such as using new transparent conductive oxide electrodes to replace traditional electrodes, reduce series resistance, and reduce energy loss during electron transmission. In addition, the development of advanced manufacturing processes, such as precise thin film deposition technology and high-temperature sintering process optimization, can improve the crystal quality and uniformity of the battery, reduce defects and impurities, thereby improving the photoelectric conversion efficiency and promoting the solar cell module to play a greater role in the energy field.
