Optimal geometrical parameters of porous layer in silicon solar cells

Abstract

In the present work we have proved theoretically and experimentally that porous silicon layers with optimal thickness can be effectively used as anti-reflection coatings in solar cells and panels. In our work we have taken into account joint mechanisms of generation and recombination of free electrons and holes in porous silicon films stimulated by photons. Experimentally these films have been grown by method of electro-chemical etching. Regularities of morphology of surfaces of the films have been investigated by use of scanning electron microscopy. Results of scanning electron microscopy, measuring of short-circuit current, open circuit voltage, and values of etching time necessary for growth of the films with required characteristics have shown that in case value of thickness of the porous layer is approximately equal to two thirds of electron diffusion length, than efficiency of the solar cell with porous layer increases by 30% in comparison with the corresponding value in the absence of texturing.