-
Product & Technology
-
-
-
-
Processflow
Boron Texturing
Process Purpose
? Removing surface contaminations and saw damage layers
? Reducing light reflection and increasing light absorption
Process methods
? Anisotropic etching occurs in a hot alkaline solution to form micron pyramid texture
Light-trapping Diagram
Boron Diffusion
Process Purpose
? Preparing uniform PN junctions to from a built-in electric field, which separates photo-generated carriers
Process methods
? Anisotropic etching occurs in a hot alkaline solution to form micron pyramid texture
boron diffusion
BSG Removal and Back Side Polish
Process Purpose
? Removing BSG layer on the back
? Back Side Polish
Process methods
? BSG Removal：Using a certain concentration of acid solutions to chemically react with the back of the silicon wafer, so as to etch the BSG on the back side.
? Alkali etching: using the etching effect of alkali to polish the back of the silicon waferetching.
Low Pressure Chemical Vapor Deposition
Process Purpose
? Providing a tunneling oxide layer to selectively pass electrons.
? The amorphous silicon layer is formed, and the passivation film layer is constructed together with the oxide layer.
Process methods
? SiO2 is formed through the reaction of oxygen and silicon under low pressure and high temperature process condition.
? SiH4 is thermally decomposed into Si and H2 under low pressure and high temperature， and the amorphous silicon layer is formed.
Phosphorus Diffusion
Process Purpose
? Polysilicon formation through high temperation crystallization process of amorphous silicon.
? At the same time, the polysilicon is doped with phosphorus to form N+ layer，Phosphorus doping in Poly to form good ohmic contact with back electrode.
Process methods
? POCl3 source is diffused at high temperature for a period of time to conduct phosphorus doping on Poly-Si.
PSG
Process Purpose
? PSG， Removing wrapped-around PSG layer on the front side of silicon wafer.
? Poly-Si，Removing the Poly-Si on the front side of the silicon wafer.
? PSG， Removing the BSG on the front side and the PSG on the back side.
Process methods
? PSG Removal : Using a certain concentration of acid solutions to chemically react with the back of the silicon wafer, so as to etch off the edge junction.
? Alkali etching: Using the etching effect of alkali to remove polycrystalline silicon film on the front surface
ALD AlOx
Process Purpose
? The field effect passivation of AlOx film is used to reduce the minority carrier recombination on silicon wafer surface
Process methods
? TMA and ozone are fed into the furnace tube, and AIOx film is grown by the method of ALD(atomic layer deposition)
Front side / Back side SiNx coating
Process Purpose
? Depositing SiNx anti- reflective thin film to reduce light reflection.
Process methods
? SiNx thin film is deposited using PECVD method through ionized decomposition of SiH4 and NH3 gas.
Screen Printing & Firing
Process Purpose
? Ag paste is printed on the surface of the silicon wafer and fired to form a conductive electrode, in order to collecting and exporting current
Process methods
? Printing back busbar and drying
? Printing back finger and drying
? Printing front busbar and drying
? Printing front finger
? Firing
? Light injection
Testing
Process Purpose
? According to the test sorting standards, the solar cells are classified by appearance, EL and electrical performance.
Process methods
? Automatic Optical Inspection
? Electroluminescent test
? IV test
? Packing
CONTACT
Headquarters: 8 Xingye Avenue, Shangrao Economic and Technological Development Zone, Jiangxi Province