Chemical compositional analysis of semiconducting bismuth sulphoselenide thin films

Abstract

A method is proposed for the chemical compositional analysis of mixed chalcogenide semiconducting thin films. The technique presently used for extraction, separation and spectrophotometric determination of bismuth(III) and selenium(IV) from hydrochloric acid media with 1-(4 1-bromophenyl) 4,4,6-trimethyl 1,4 dihydropyrimidine 2-thiol (4 l-bromo PTPT) in chloroform. In acidic conditions (0.3 M HCl) bismuth form a yellow coloured complex with 4 l-bromo PTPT is extracted in chloroform with an absorption maxima 410 nm. In strong acidic conditions (5.5 M HCl) selenium forms yellow complex with the ligand extracted in chloroform which shows absorption maxima 350 nm. The absorbance of bismuth(III) sample in 0.3 M HCl is increases linearly in the concentration range 2–16 ppm. In case of selenium absorbance is increases linearly in the concentration range 10–75 ppm. We propose an extractive spectrophotometric determination method for bismuth and antimony chalcogenide semiconducting thin films. The proposed method is sensitive, selective, rapid, reproducible and has been satisfactorily applied for the separation and determination of trace amounts of Bi(III) from Se(IV) as well as Bi(III) from Sb(III) in presence of Se(IV) from mixed bismuth sulphoselenide thin films. The spectrophotometric determination of the metals requires approximately 15–20 min. Large number of diverse ions with various concentrations are studied to test the reproducibility and sensitivity of the method for the trace analysis of mixed chalcogenide thin films.