2 research outputs found
Characterization Ni/Ag Thin Films
Thin films of silver sulfide (Ag2S) have been chemically deposited from an alkaline bath, using sodium thiosulphate as a sulphur source, onto glass and metal substrates (Ni) by a simple and economical electroless chemical deposition technique. Their structural, optical and electrical properties have been studied. X- ray studies of the films showed that the as-prepared films of Ag2S were a mixture of both amorphous and polycrystalline phases, while Ag2S/ Ni films were found to be polycrystalline. Annealing of the films of Ag2S and Ag2S/ Ni at 200 ºC for 3 h led to further crystallization. The films contained a random distribution of small crystallites and at annealing temperature 200°C show the over-growth of particles on the smooth film surface. The optical band gap of the Ag2S thin films was evaluated from the analysis of the absorption spectra and estimated to be between 2.2 eV- 2.4 eV. Rise and decay of photoconductivity was studied at room temperature. The sheet resistance was 106 Ω/ square and electrical resistivity is of the order of 102-103 Ω cm, determined by Van der Pauw four- point probe method. Sheet carrier density, hall mobility can be determined from Hall Effect measurement. Variation of magnetoresistance and Hall voltage measurement was determined