Controlling neutral mixtures : Thin film deposition via laser ablation and selective ionization of K4In4Sb6

We present experimental results on a technique that combines laser ablation with selective ionization in order to generate and subsequently separate neutral mixtures. For example, in the laser ablation (λ = 308 nm) of K4In4Sb6, irradiation of the ablation plume with 248 nm laser light induces selective ionization of potassium. Subsequent electric field extraction leads to macroscopic depletion of potassium from the ablation plume. Quantification via scanning Auger electron spectroscopy of thin films deposited from such ablation plumes reveals that even without optimization of the spatial overlap between the ablation plume and the ionization laser, the technique leads to ∼60% removal of potassium. While at present it is not clear whether conditions exist for full quantitative removal of the potassium, it is apparent that control over the neutral plume has been exerted.