High-Power 355 nm Ultraviolet Laser for edge insulation of solar cells

Solar energy is a renewable energy, green and environmentally friendly. Solar cells can convert light energy into electrical energy, which is of great significance to promoting the optimization and transformation of my country's energy structure under the "two-carbon" strategy. And go.

The application of laser processing in the production process of solar cells is very common. The addition of laser technology has become an important means to improve the efficiency of solar cells. For example, in the production of perovskite solar cells, laser etching is used to scribe the P1/P2/P3 process. To achieve the purpose of blocking conduction, ensure the insulation between the batteries, and make them form a separate module. Laser etching has high precision, and does not damage substrate materials, substrate glass, etc., thereby effectively reducing the area of ​​inactive areas and improving module efficiency; crystalline silicon solar cells use laser doping technology, which can not only reduce the diffusion layer minority carrier recombination Efficiency, improve the short-wave response and open-circuit voltage of the battery, can also reduce the battery series resistance, improve the battery short-circuit current and fill factor, thereby improving the conversion efficiency. In addition, non-contact processing can make thin, brittle battery materials free from mechanical stress, such as laser-cut crystalline silicon solar panels, with neat edges, small chipping, and high yields.

Edge insulation of crystalline silicon solar cells with High-Power 355 nm Ultraviolet Laser is another typical application of laser processing solar cells.

The researchers found that during the fabrication of c-Si cells, N-type ions were doped/diffused into the P-type silicon substrate to form a micron-scale N-type doped film, which surrounded the entire wafer, causing the front and back sides of the cell. The shunt of the electrode, which is prone to energy loss due to leakage current.

In order to avoid shunting, the edge of the battery must be insulated. Traditional processes use plasma to treat edge insulation, but the etching chemicals used are expensive and environmentally harmful. Laser edge insulation, which is more environmentally friendly and energy efficient, is achieved by scribing trenches as close as possible to the outer edge of the solar cell. For the best insulating effect, the depth of the trench must be greater than the ion diffusion layer. High-Power 355 nm Ultraviolet Laser has short wavelength, narrow pulse width (about 25ns), high beam quality (M2<1.2), high peak power and high repetition frequency (single pulse-500kHz) can bring high precision, uniform and smooth insulation underline. With the laser-shaped grooves, energy losses due to solar cell leakage currents are greatly reduced.