ELECTRODEPOSITION OF LEAD SULFIDE IN ACIDIC MEDIUM

Polycrystalline thin films of lead sulphide were electrodeposited on t itanium, aluminium and stainless steel (SS) substrates at a constant p otential of -0.7V vs. Ag\AgCl\(sat)KCl electrode using 1 mM solutions of Pb(NO,), and Na2S2O3 at pH2.7, 2.8 and 2.9. Except at pH 2.9 (which also gave tetragonal PbS2) all other pHs gave single phase PbS (fee). While deposition on Al gave a crystalline phase of PbS with very prom inent (200) and (111) planes, that on SS substrate showed growth of th e (200) plane only. Although the deposition of PbS on Ti was good, it showed (111) and (200) planes of low intensity compared to that on Al. Film thickness and grain size were found to be of the order of microm etres. The cyclic voltammetry of the film formation was studied in a p otential range -1 to OV (Ag\AgCl) followed by XRD, SEM and AFM analyse s. The mechanism of growth is discussed. (C) 1997 Elsevier Science S.A .