Fabrication and Optimization of Silicon Solar Cell Characteristics by Using Porous Silicon Layers on the Front and Back Sides

Abstract

Porous silicon layer (PSL) has emerged in potential solar cell applications because of its high surface area to volume ratio, convenient surface chemistry and large energy band gap ≈1.9 ev. PSL has been prepared from n+p/Si junction using electrochemical etching (ECE) with three different current densities 25, 50 and 75 mA/cm2 on the front and back side of the junction. The influence of varying current density on morphological, optical, chemical and electrical properties of PS has been inspected. SEM micrographs showed that the surface porosity of 90% on the front side, in contrast the etched back surface seemed in harmonic shape with identical pore size and porosity of 98%. The PL spectrum peak ranged from 640 to 670 nm. PSL formed on both sides has the lowest reflectivity at current density of 50 mA/cm2. The obtained FTIR spectra of the samples with a relatively high PL intensity exhibit a developed broad transmission bands in the range of 600 to 4000 Solar cell conversion efficiency of PSL formed on both sides is increased to 17% compared to other workers. Solar cell based on PSL formed on both sides provides stability and it is recommended for industry manufacturing.