Synthesis and characterization of zinc tin sulphide (ZTS) thin films via chemical bath deposition route
Abstract:Zinc Tin Sulphide (ZTS)
thin films were deposited on glass substrates by Chemical Bath Deposition (CBD)
technique. The CBD was obtained by preparing 20 ml of 0.5M of Zinc chloride
solution, 20ml of 0.5M stannum chloride (SnCl2) with 3ml of
Triethanolamine (TEA) (N(CH2CH2OH)3) and 25ml
of 0.5M of Thiourea as complexants. The grain size of ZTS from the SEM
micrographs was spherically-shaped without visible defects like crack or peel.
The SEM micrograph of the annealed ZTS thin films, however, showed a dense
sponge-like structure. ZTS thin films reflectance curve exhibited
average reflectance below
30% for all films. Annealed ZTS thin films (at 200 0C) exhibited the
greatest reflectance
of about 30% than all other films. Both as-deposited and annealed ZTS films exhibited transmittance above 40% for
wavelength around 780 nm and above. The extrapolated band
gaps energy values for ZTS for as-deposited and annealed thin films varied from
the range of 3.30 to 3.40 eV. The resistivity increased with an increase
in heat treatment and
it ranged between, 1.83 × 10-1 Ωm to 9.71 × 10-2 Ωm