Electrodeposition of Nanomodulated Electronic Ceramic Thin Films

Electrochemistry can be used for the atomic-level architecture of ceramic materials. In this report, ceramic superlattices based on the Tl _a Pb _b O _c /Tl _d Pb _e O _f system were electrodeposited with individual layer thicknesses as thin as 3 nm. The superlattices were deposited from a single aqueous solution at room temperature, and the layer thicknesses were galvanostatically controlled. Substitution of Tl ₂ O ₃ into PbO ₂ appears to stabilize a face-centered cubic structure with an average lattice parameter of 0.536 nm. The lattice parameters for the Tl _a Pb _b O _c mixed oxides vary by less than 0.3% when the Pb/Tl ratio is varied from 0.84 to 7.3. Because the modulation wavelengths are of electron mean free path dimensions, this new class of degenerate semiconductor metal-oxide superlattices may show thickness-dependent quantum optical, electronic, or optoelectronic effects.