Effect of bismuth oxide nanoparticles on the physicochemical properties of porous silicon thin films

International audienceIn this work, bismuth oxide nanoparticles were successfully deposited on porous silicon (PSi) in order to enhancethe light absorption and reduce the optical losses. The obtained bismuth oxide (Bi2 O 3)/PSi samples were characterizedby means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electronmicroscopy (SEM) combined with energy-dispersive spectroscopy (EDS), atomic force microscopy (AFM), photolumines-cence (PL), UV–visible absorption and reflection spectroscopy techniques. The XRD studies revealed the formation of themonoclinic α-Bi2 O3 phase. The XPS analysis demonstrates the formation of highly pure Bi 2 O 3 nanoparticles in accordancewith XRD results. The SEM and AFM analyses confirmed that the bismuth oxide nanoparticles are well incorporated anduniformly distributed over the surface of PSi without changes in the arrangement and shape of the pores, resulting in anoptimized microstructure. The Bi2 O 3/PSi films showed better absorption than PSi layers as indicated by UV–Vis absorptiontechnique. The reflection measurements confirmed a further reduction in reflectivity of PSi from 6.4 to 3.5% after the inclu-sion of Bi 2 O 3 nanoparticles, which is of significant importance for solar cells application since it can enhance its conversionefficiency. The Bi2 O3/PSi films have a great promise to be used as efficient antireflection coatings in innovative conceptsof higher efficiency and cost-effective solar cells