Hierarchical structure transformation and surface modification of solvothermal method synthesized SnS with oleic acid in ethylene glycol solvent were discussed in detail. The structural, optical, and morphology of as prepared SnS samples were examined by X-ray diffraction (XRD), Raman Spectroscopy, and Field Emission Scanning Electron Microscopy (FE-SEM). XRD verifies the orthorhombic crystal structure of the SnS phase for all synthesized samples. Single-phase nature of synthesized particles was confirmed with Raman characterization. Morphology evolution of SnS from regular to hierarchical structures upon adding oleic acid is performed through FE-SEM analysis. Junction diodes p-SnS/n-Si fabricated with different oleic acid concentrations (0.5, 1.5, and 2.5 mL) synthesized SnS particles show better photo-response, which can be used in photodiode applications.