Surface Texturization and Interface Passivation of Mono and Polycrystalline Silicon Substrates Evaluation of the Wet Chemical Treatments by UV NIR Reflectance

The relations between light trapping behavior, structural imperfections, energetic distribution of interface state densities and interface recombination losses were investigated on as cut, saw damage etched and textured mono crystalline silicon substrates for solar cell manufacturing. Surface sensitive techniques, the field modulated surface photovoltage SPV , total hemispherical UV NIR reflectance measurements and electron microscopy SEM were employed to yield detailed information on the influence of wet chemical treatments on preparation induced texture, nano roughness and electronic properties of polished and textured silicon substrates. The correlation between UV reflectance and SPV measured surface state density has been investigated. As a result, the different contributions of micron sized texture and nanometer sized surface roughness to the reflectance signal have been separated and a measurement set up and optical model for routine evaluation of wet chemical surface texturization in production processes has been establishe