Research On Textured Technology Of Silicon Solar Cell System

In conventional KOH texturing system, new texturing process conditions were attempted: By adding a small amount of an acid or a surfactant to enhance the effect of textured silicon wafer. The principle is the adding of an acid not only can slow down the reaction rate of silicon wafer with acid, but also as a nucleating agent to increase the nucleation starting point of the pyramid. Adding an aqueous solution of surfactant can increase the wettability of the silicon wafer, so that the resulting pyramid textured more intensive.With potassium hydroxide and ethanol as a basic reaction system, the concentrations of KOH, the reaction time and temperature conditions to obtain a good textured result were studied. The best KOH concentration, reaction time and reaction temperature were obtained. Under optimal conditions, some texturing additives, such as acids or surfactants were added. Texturing conducted under different process conditions, such as different textured KOH concentration, the reaction time and temperature conditions. When the mass concentration of 1.5% KOH, texturing time 60min, texturing temperature 80℃, the best reflection of silicon texturing was obtained, 73.45% of pre-texturing. The adding of additives has a role to promote texturing. The adding of a certain amount of acid such as boric acid, sulfonic acid, tartaric acid, acrylic acid, acetic acid and the like in the texturing solution could reduced the reflection of silicon wafer. The lower reflection could be obtained with the adding of mixed acid. The relative reflectance of 40.81% was obtained with the adding of 100ppm of tartaric acid and boric acid mixed. Finally, adding of a certain amount of surfactant in the system, such as PEG400, gelatin, sorbitol, sodium dodecyl sulfate, methyl cellulose, smaller size, more uniform surface and lower reflectivity texturing structure could be obtained. Wafer surface reflectivity reduced to 64.32% of the original when gelatin was added.