Investigation of Hf/H_2o_2 Concentration Effect on Structural and Antireflection Properties of Porous Silicon Prepared By Metal-Assisted Chemical Etching Process For Photovoltaic Applications

Porous silicon was successfully prepared using metal-assisted chemical etching method. the effect of hf/h_2o_2 concentrations on the porosity type and size was investigated as an effective parameter in etching solution. various structures can be synthesized by implementing different regimes of ρ which is the function of molar ratio of hf/h_2o-2. it is found that the best achieved etching rate is equal to 85%. field emission electron microscopy (fe-sem) confirmed that all etched samples have porous structure and the sample which was immersed into hf/h_2o_2 with molar ratio of 7/3.53 has the smallest porosities. the average roughness of 288 nm and reflectivity as low as 7% could be achieved using this molar ratio. the raman peak appeared at 520.09 cm^-1 confirmed that there weren’t any defect and stress in the porous structure. current density-voltage characterization was done for investigation important parameters of the prepared solar cells which had different structures. so it was shown that the porous sample immersed into hf/h_2o_2 with molar ratio of 7/3.53 had jsc and voc equal to 0.118acm^-2 and 0.56v, respectively. the prepared porous silicon is a potential candidate for replacing antireflective layers in photovoltaic devices because of its low production cost, high antireflective property, and possibility of integration process relative to other antireflection layers.