Optimization of MACE black silicon surface morphology in multi-crystalline wafers for excellent opto-electronic properties

Low cost metal assisted chemical etching (MACE) based black silicon (b-Si) texturization process is demonstrated for diamond wire sawn (DWS) multi-crystalline (mc-Si) wafers. Acid etching followed by diluted alkaline solution based polishing processes are used for modifying the b-Si surface for suppressing the heavy recombination associated with b-Si surfaces. Surface modification of b-Si results in random inverted pyramid textures with balanced optical and electrical properties. Correlation between surface morphology and its opto-electronic properties are investigated in detail. Low weighted average reflectance of 16.8% (without ARC) and minority carrier lifetime of 72 μs is reported for optimized b-Si modified textured mc-Si wafers.