Second Harmonic Generation in Chemical Vapor Deposition Synthesized CuS Crystals

Abstract

Copper sulfide (CuS) has garnered significant attention in various fields of application due to its unique electronic, optical, and catalytic features. In this study, we present the chemical vapor deposition (CVD)-based synthesis of ultrathin CuS crystals as thin as 14 nm with lateral sizes up to 60 um. The structure, morphology, and composition of the as-synthesized CuS crystals were thoroughly characterized. Among our results, we measured the first-order temperature coefficients of Raman shifts of CuS. Moreover, we showed that CuS crystals exhibited an unexpected second harmonic generation (SHG), which is attributed to the presence of defects in the CuS lattice. Our results suggest that single crystalline CuS possesses a considerable potential for nonlinear optical applications in conjunction with its current applications in electronics and catalysis.