Inverted pyramid texturisation without photolithography for multicrystalline solar cell

New surface texturing method including formation of inverted pyramids has been further investigated in this study. Electroless deposition of Ag particles as metal catalyst in HF/H₂O₂ etching solution is found to be efficient for drilling nano-size holes into c-Si or m-Si. After etching back by KOH solution, the inverted pyramids structure gradually appears in c-Si (100) surface. Although the m-Si wafers have different orientation grains, the average reflection after texturing demonstrates lower than that of traditional acid treatment. The new texturing wafers were processed into cells with a conventional process including POCl₃ diffusion (leading to 65 Ω/□), removal of native oxide by BOE solution. The deviations of sheet resistance on 5" wafers are controlled below 5% which are consistent with that of acidic or alkaline treatment wafers. The SiNx antireflection coating was deposited uniformly by PECVD deposition. From the results of IV measurement, the conversion efficiency of new texturing has 0.1% higher than that of acidic treatment (texturied by Rena facilities). We expect the optimization of texturisation will lead to more short-circuit current density( J_sc) and gain more conversion efficiencies.