Surface morphological study of SILAR grown Ag2S thin films

Abstract

Silver sulfide (Ag₂S) thin films were deposited on glass substrates using the successive ionic layer adsorption and reaction (SILAR) technique, and their surface morphology was systematically investigated using atomic force microscopy (AFM). The AFM analysis revealed uniform and compact surface features with well-distributed grains across the substrate, indicating homogeneous film growth achieved through the SILAR process. Quantitative surface parameters such as average roughness (Ra), root mean square roughness (Rq), and grain size were evaluated as a function of the number of SILAR cycles. The results showed that surface roughness and grain size increased gradually with increasing deposition cycles, reflecting progressive nucleation and coalescence of Ag₂S nanocrystallites. Three-dimensional AFM images confirmed the formation of densely packed grains with good surface coverage and minimal voids. The observed surface morphology suggests improved film continuity and adhesion, which are desirable for optoelectronic and sensing applications. This study demonstrates that AFM is an effective tool for understanding the growth mechanism and surface evolution of SILAR-grown Ag₂S thin films.