Effect of silver, gold, and platinum substrates on structural and optical properties of tilted nanocolumnar SnS films

Tin (II) sulfide films with tilted nanocolumns have been grown using thermal evaporation method on silver, gold, and platinum substrates. A number of samples were prepared at different vapor flow angles (α = 0°, 35°, and 75°) with respect to the substrate normal for studying the effects of both substrate type and growth angle. Structural and optical properties of the specimens were systematically investigated. Remarkable variations have been concluded in structural properties of the specimens as a result of employing different substrate types and growth angles. The morphological study confirmed the emergence of growth plates in nanoscale thicknesses, which are also altered due to substrate type and their growth angles. Furthermore, according to the Raman spectra of the samples, the presence of active modes characteristics for the SnS and other phases of SnS compound has been verified. The spectral analysis of atomic force microscopy of the specimens revealed the influence of substrate type and growth angle on the average surface roughness of the samples. Finally, the optical band gap of the samples estimated using Kubelka-Munk equation showed how it varies considerably by changing the substrate type and employing different growth angles.