Abstract
Tin sulphide (SnxSy) thin films have been prepared on Pyrex glass substrates by the spray pyrolysis technique using tin chloride (SnCl2) and n, n-dimethylthiourea (CH3NHCSNHCH3) as starting materials. The depositions were carried out in the range of substrate temperatures from 320 to 450 degrees C. From X-ray diffraction measurements and SEM micrographs, it is found that the values of x and y, which determine the type of deposited compound, depend on the substrate temperature. At lower substrate temperatures (320-360 degrees C), mixed phases such as Sn2S3 and gamma -Sn2S3 are present. At intermediate substrate temperatures (370-390 degrees C), the SnS phase is predominant. For substrate temperatures higher than 390 degrees C the deposited material is mainly SnO2. The optical reflectance and transmittance of SnS were used in an iterative method to obtain the refractive index (n) and the extinction coefficient (k). These values of n and k were used to calculate the absorption coefficient ( alpha ) and the bandgap (EG), giving the result EG=1.27 eV. Measurements of the dark conductance ( sigma ) as a function of T were made and an activation energy of 0.54 eV was determined from the slope of a plot of ln sigma versus 1/T.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call