Stepwise growth of size-confined CdS in the two-dimensional hydrophilic interlayers of Langmuir–Blodgett films by the repeated sulfidation–intercalation technique

Abstract

When a CdS-bearing stearic acid multilayer produced by exposing a cadmium stearate Langmuir–Blodgett (LB) film to H₂S gas is immersed in aqueous CdCl₂, Cd ions are intercalated to regenerate the cadmium stearate multilayer without the escape of CdS. The repetition of sulfidation–intercalation cycles allowed the size-quantized CdS to grow in a stepwise fashion in the hydrophilic interlayers. The layered structure was maintained throughout the repeated cycles, although the multilayer-constructing stearate molecules became less oriented by the formation and growth of CdS. The formation of a two-dimensional CdS plane was suggested.