RBS analysis of Langmuir-Blodgett films bearing quantum-sized CdS particles

Rutherford backscattering spectrometry is applied to an analysis of the structure of Langmuir-Blodgett (LB) films bearing quantum-sized cadmium sulfide particles (Q-CdS). Cadmium arachidate LB films before and after exposure to hydrogen sulfide are analyzed using a beam of 2 MeV 4He2+. The change in the Cd-edge is ascribed to the Cd migration toward the substrate, which suggests that a well-ordered layer structure of the original film is disordered during Q-CdS formation. This finding indicates that the Q-CdS produced in hydrophilic interlayers cannot be two-dimensional platelets but are spherical particles.