In situ growth of CuS thin films on functionalized self-assembled monolayers using chemical bath deposition

Nano-structured CuS thin films were deposited on the functionalized –NH2-terminated self-assembled monolayers (SAMs) surface by chemical bath deposition (CBD). The deposition mechanism of CuS on the –NH2-terminated group was systematically investigated using field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscope (XPS), UV–vis absorption. The optical, electrical and photoelectrochemical performance of CuS thin films incorporating with the X-ray diffraction (XRD) analysis confirmed the nanocrystalline nature of CuS with hexagonal crystal structure and also revealed that CuS thin film is a p-type semiconductor with high electrical conductivity (12.3 Ω/□). The functionalized SAMs terminal group plays a key role in the deposition of CuS thin films. The growth of CuS on the varying SAMs surface shows different deposition mechanisms. On –NH2-terminated surfaces, a combination of ion-by-ion growth and cluster-by-cluster deposition can interpret the observed behavior. On –OH- and –CH3-terminated surfaces, the dominant growth mechanism on the surface is cluster-by-cluster deposition in the solution. According to this principle, the patterned CuS microarrays with different feature sizes were successfully deposited on –NH2-terminated SAMs regions of –NH2/–CH3 patterned SAMs surface.

The –N of APTS–SAMs can form complexes with Cu2+ in the planting solutions, and then, the heterogenous nucleation reaction incessantly takes place on the interface.Figure optionsDownload high-quality image (31 K)Download as PowerPoint slideResearch highlights
► CNH2-terminated SAMs is required in order to obtain CuS thin films with good quality.
► The CuS films on the APTS-SAMs show obvious photoelectrochemical response.
► The growth of CuS on the varying SAMs surface shows different deposition mechanisms.