Layer-by-layer self-assembly of composite films of CdS nanoparticle and alkanedithiol on gold: an X-ray photoelectron spectroscopic characterization

Layer-by-layer self-assembly of composite thin films of cadmium sulfide (CdS) nanoparticle and alkanedithiol was achieved on a gold substrate by an alternate immersion into solutions of dithiols (1,6-hexanedithiol and 1,10-decanedithiol) and solution containing CdS nanoparticles (ca. 3 nm in diameter). The layer-by-layer structure was confirmed by angle-resolved X-ray photoelectron spectroscopy (XPS) at each composite-film preparation step. The proposed structure and mechanism of self-assembly were in agreement with our previous results obtained by Fourier transform infrared reflection-absorption spectroscopy.