Kapton polyimide is known for its high thermal stability, >400 • C. Copper sulfide thin films of 75 and 100 nm thickness were coated on DuPont Kapton HN polyimide foils of 25 µm thickness by floating them on a chemical bath containing copper complexes and thiourea. The coated foils were annealed at 150-400 • C in nitrogen, converting the coating from CuS to Cu 1.8 S. The sheet resistance of the annealed coatings (100 nm) is 10-50 / and electrical conductivity, 2-10×10 3 −1 cm −1 , which remain nearly constant even after the foils are immersed in 0.1-1 M HCl for 30-120 min. The coated polyimide has a transmittance (25-35%) peak located in the wavelength region 550-600 nm, with transmittance dropping to near zero below 450 nm and below 10% in the near-infrared spectral region. These characteristics are relevant in solar radiation control applications. The coated foils might also be used as conductive substrates for electrolytic deposition of metals and semiconductors and for optoelectronic device structures.

Copper sulfide thin films of 75 nm and 100 nm thickness were coated on Kapton foils (PI) of 25 rim thickness by floating them on a chemical bath. The foils were annealed at 150°C-400°C in N 2 converting the coating from CuS to Cui.gS. The sheet resistance of the annealed coatings (100 nm) is 10-50 ohms/square which is almost unaltered after immersion in dilute HC1 for 30-120 min. The infrared reflectance predicted for the coatings is 67%-77% at a wavelength 2.5 urn, which is nearly what is experimentally observed. The coated PI has a transmittance (25-35%) peak located around 550-600 nm. These thermally stable conductive coatings on PI foils might be used as conductive substrates for optoelectronic device structures.

Thin films of NiS have been deposited on indium doped tin oxide coated conducting glass substrates using electrodeposition technique. Structural studies revealed that the deposited films exhibit hexagonal structure with preferential orientation along (002) plane. Structural parameters such as crystallite size, strain and dislocation density are calculated for films with different thickness values obtained at various deposition time. The film composition and surface morphology have been analyzed using scanning electron microscopy and energy dispersive analysis by X-rays. Optical absorption analysis showed that the deposited films possess band gap value around 0.7 eV.

Electrodeposited CdZnSe thin films have been prepared at various bath temperatures. The thickness of the films was estimated between 850 nm and 1500 nm by stylus method. The X-ray diffraction patterns revealed that the polycrystalline nature with cubic structure of CdZnSe alloy thin films. Microstructural properties such as, crystallite size, dislocation density, microstrain and number of crystallites per unit area were calculated using predominant orientation of the films. SEM images revealed that the surface morphology could be tailored suitably by adjusting the pH value during deposition. The surface roughness of the film was estimated using topographical studies. Optical properties of the film were analyzed from absorption and transmittance studies. Optical band gap of the films increased from 1.67 to 1.72 eV with the increase of bath temperature from 30 to 90℃. The optical constants (refractive index (n) and extinction coefficient (k)) of CdZnSe thin films were evaluated using optical studies.

Growth of lead sulphide thin films has been carried out electrochemically on indium doped tin oxide coated conducting glass substrates from an aqueous acidic bath containing Pb(CH3COO)2 and Na2S2O3. X-ray diffraction pattern showed that the deposited films possess cubic structure with most prominent reflection along (200) plane. The dependency of microstructural parameters such as crystallite size, strain and dislocation density with film thickness has been analyzed. Surface morphology and film composition have been analyzed using scanning electron microscopy and energy dispersive analysis by X-rays. Optical absorption analysis showed that the prepared films possess a direct band gap value of 0.37 eV.