Structural, optical and electrical properties of chemically deposited silver sulfide thin films

Abstract

Ag 2 S thin films of 90-300 nm thickness were deposited in 3-8 h at 60-70 • C on glass substrates from a chemical bath containing silver nitrate, sodium thiosulfate and dimethylthiourea (DMTU) or tetramethylthiourea (TMTU). The glass substrates used for this purpose were previously immersed in a chemical deposition bath to deposit a ZnS thin film of 40 nm thickness in the case of the bath with DMTU or subjected to a pretreatment in a methanol solution of 3-(trimethoxysilyl)propyl methacrylate for deposition from the TMTU bath. Thin film yield is >40% for the TMTU bath, when the deposition produces 60 nm films at a substrate separation of 0.4 mm, and is about 30% for film thicknesses of 90-300 nm for both baths at a substrate separation of 1-5 mm. X-ray diffraction patterns similar to that of the mineral acanthite (Ag 2 S) are observed in the case of the films heated in nitrogen at temperatures 100-200 • C; heating at 300-400 • C leads to freezing-in of the high temperature phase, argentite. Films annealed at 300 • C possess a direct (forbidden) optical band gap of about 1.0 eV. Typical electrical conductivity of the films is 10 −3 ( cm) −1 . A photosensitivity of approximately 100 is observed in films annealed at 200 • C, under an intensity of illumination 2 kW m −2 from a tungsten halogen lamp. Mobility-lifetime product is of the order of 10 −5 cm 2 V −1 , which suggests a free carrier lifetime of about 0.1 µs.

Photocurrent enhancement of the CdS/TiO 2 /ITO photoelectrodes achieved by controlling the deposition amount of Ag 2 S nanocrystals

“…This prepared monocline and anatase bi-crystalline TiO 2 has better electrical properties than pure anatase titanium nanoparticles because the charge separation of photogenerated electrons-holes in a monocline and anatase bi-crystalline TiO 2 becomes more effective [45,46]. The diffraction peaks of Ag 2 S (marked with A) can be indexed to a monoclinic acanthite phase of Ag 2 S (α-Ag 2 S), which is in agreement with the literature (PDF# 14-0072) [47]. Moreover, the well defined diffraction peaks (marked with C) corresponding to the (033), (042), (107) lattice planes of reflections indicated the formation of CdS nanoparticles with an orthorhombic phase (PDF# 47-1179).…”

Recent status of chemical bath deposited metal chalcogenide and metal oxide thin films

“…Rodrguez et al [89] obtained Ag 2 S thin films using thiosulphate as a complexing agent and dimethylthiourea and tetramethylthiourea as sulphide ion sources. These films showed good uniformity and adherence on ZnS coated and organosilane treated glass substrates.…”

Synthesis and Characterization of Ag2S Layers Formed on Polypropylene

“…Polymers modi�ed by thin electrically conductive or semiconductive �lms of binary inorganic compounds, particularly of metal chalcogenides [1][2][3][4] represent a new class of materials-composites. e application of these composites is determined by their properties, wheares the latter depend signi�cantly on the preparation method, even the chemical composition and structure of composites slightly change [5,6].…”