Electrodeposition of In2Se3 Using Potential Pulse Atomic Layer Deposition

Indium(III) selenide, In2Se3, thin films were electro-deposited at room temperature from an aqueous solution containing ionic precursors for both In and Se, using potential pulse atomic layer deposition (PP-ALD). Cyclic voltammetry was used to determine approximate cycle potentials, and anodic and cathodic potentials were systematically examined to optimize the potential pulse program for In2Se3. Electron probe microanalysis was used to follow the In:Se atomic ratio as a function of the cycle conditions, and annealing studies were performed on stoichiometric deposits. Film thickness was a function of both the anodic and cathodic potentials. The optimum growth rate was consistent with previous PP-ALD studies in which similar concentrations and pulse times were employed, 0.02 nm/cycle. The use of the potential pulse cycle for film growth resulted in surface-limited control over the deposit stoichiometry each cycle and thus a layer-by-layer growth process.