Solar panels are divided according to the battery structure. At present, we divide them into 4 major sections. As for the 4 major sections, which one has more advantages, see the following introduction for details:
1. Homojunction solar cells P-N junctions formed by the same semiconductor material are called homojunctions, and solar cells formed with homogeneous structures are called homojunction solar cells.
2. Heterojunction solar cells A junction formed by two semiconductor materials with different forbidden band widths is called a heterojunction, and a solar cell formed with a heterostructure is called a heterojunction solar cell.
3. Schottky junction solar cell A solar cell constructed using a Schottky barrier at the metal-semiconductor interface is called a Schottky junction solar cell, or MS cell for short. Has been developed into metal-oxide-semiconductor (MOS), metal-insulator-semiconductor (MIS) solar cells and so on.
4. Composite junction solar cell A solar cell formed by two or more PN junctions is called a composite junction solar cell, and is divided into a vertical multi-junction solar cell and a horizontal multi-junction solar cell, such as a (MIS) solar cell and a The stacking of PN junction silicon cells can form high-efficiency MISNP composite junction silicon solar cells, whose efficiency has reached 22%. Composite junction solar cells are often made in cascade type. A wide bandgap material is placed in the top area to absorb high-energy photons in the sunlight. A narrow bandgap material is used to absorb low-energy photons to broaden the spectral response of the entire cell. The efficiencies of AlGaAs-GaAs-Si solar cells currently developed are as high as 31%.