GROWTH OF STRONGLY ORIENTATED LEAD SULFIDE THIN-FILMS BY SUCCESSIVE IONIC LAYER ADSORPTION AND REACTION (SILAR) TECHNIQUE

Lead sulfide thin films were grown at room temperature by the successi ve ionic layer adsorption and reaction (SILAR) technique on soda lime glass, ITO and Al2O3 covered glass, SiO3 (100)Si and (111)Si substrate s. SILAR utilises sequential treatment of the substrate with aqueous p recursor solutions. Dilute solutions of lead acetate and thioacetamide were used as precursors for Pb2+ and S2-, respectively. The lead prec ursor solution also contained triethanolamine (tea) as a complexing ag ent, with a Pb:tea mole ratio of 1:2. On glass the growth rate was 0.1 2 nm per cycle with 0.2 mol dm(-3) lead and 0.4 mol dm(-3) thioacetami de solution. The appearance of the films was metallic. X-Ray diffracti on studies revealed a strong [200] orientation of the films. According to the Rutherford back-scattering (RBS) and nuclear reaction analysis (NRA) results the films were stoichiometric PbS and contained small a mounts of some lighter impurities, possibly O and H. Scanning electron microscope (SEM) images revealed that the films were rather rough and consisted of grains with a diameter approximately corresponding to th e thickness of the film.