Solar cells are devices that directly converts light energy into electrical energy through photoelectric effect or photochemical effects.
Under the irradiation of electromagnetic wave higher than a certain frequency, electrons inside some substances are excited by photons to form electric current, that is, photogenerated electricity.
The basis of the working principle of solar cells is the photovoltaic effect of the semiconductor PN junction. The so-called photovoltaic effect is a kind of effect that when the object is illuminated, the charge distribution state in the object changes and produces electromotive force and current. In short, the sun's illumination causes the photovoltaic panel to generate a voltage.
The so-called HIT structure is to deposit an undoped (eigen) hydrogenated amorphous silicon film and a doped hydrogenated amorphous silicon film with the opposite of crystalline silicon doping type on the crystalline silicon wafer. After adopting this process measure, the performance of PN junction is improved.
The coating technology required for solar cells: PECVD systems and sputter coatings.
PECVD: It is used in various test sites such as graphene preparation, sulfide preparation, and nanomaterial preparation. Various films such as SiOx, SiNx, amorphous silicon, microcrystalline silicon, nano-silicon, SiC, diamond-like, etc. can be deposited on the surface of a sheet or similar shaped sample, and p-type and n-type doped films can be deposited. The deposited film has good uniformity, compactness, adhesion, and insulation. Widely used in cutting tools, high-precision molds, hard coatings, high-end decoration and other fields.
Plasma enhanced CVD system(PECVD)
Magnetron sputtering is a type of PVD. The general sputtering method can be used to prepare a varity of materials such as metal, semiconductor, insulator, etc., and has the advantages of simple equipment, easy control, large coating area, and strong adhesion.