Improvement of multicrystalline silicon solar cell performance via chemical vapor etching method-based porous silicon nanostructures

In this paper, we report on the effect of chemical vapor etching-based porous silicon (PS) on the performance of multicrystalline silicon solar cells performed via deep n+/p junction-type structures. Chemical vapor etching of silicon leads to the formation of porous silicon (PS) nanostructures that dramatically decrease the surface reflectivity from 30% to about 8%, and increase the minority carrier diffusion lengths from 90 μm to 170 μm. As a result, the short-circuit current density was improved by more than 20% and the fill factor (FF) by about a 10%. An enhancement of the photovoltaic conversion energy efficiency of the solar cells from 7% to 10% was observed. This low-cost PS formation process can be applied in the photovoltaic cell technology as a standard procedure.

► Chemical vapor etching of mc-Si leads to the formation of porous silicon (PS).
► This treatment dramatically reduce the surface reflectivity and raise the minority carrier diffusion lengths.
► PS layer reduces the recombination velocity at the grain and GBs and enhanced the internal quantum efficiency.
► An enhancement of the photovoltaic conversion energy efficiency of the solar cells was observed.