Formation of porous nanostructured lead telluride films by an anodic electrochemical etching method

Comprehensive research of the structural, optical and electrical properties of a PbTe/CaF2/Si(1 1 1) epitaxial system after anodic electrochemical treatment in a Norr solution electrolyte with a low current density of 6 mA cm−2 was carried out. It is shown that the anodizing results in the increase of the band gap and resistivity and in the decrease of the refractive index of lead telluride. Using secondary ion mass spectrometry, a specific change of the C, K, H element distribution in depth of PbTe films after electrochemical treatment was detected. It is demonstrated that the set of presented experimental results can be explained from the standpoint of the formation of a mesoporous structure of lead telluride with a porosity value of about 50%. The effective radius of PbTe nanoparticles is equal to 13 nm. Triple-crystal x-ray diffractometry results analysis showed that the pores have spherical voids with an average dimension of 40 nm.