| Experimental results, related to a novel laser-assisted technique for deposition of III-V semiconductor thin-films, are presented. The method involves precursors in the form of I-III-V Zintl-phase materials. While such compounds exhibit a variety of useful properties, the presence of the group I element is a major concern--in terms of the desired final product it can be considered a major impurity that has to be removed. To address this situation, we employ a strategy, based on the difference in the ionization potentials for the constituent elements, that can be described in brief as (i) laser ablation of a I-III-V compound, (ii) removal of the group I element by selective gas-phase laser ionization and extraction in an electric field, and (iii) subsequent re-deposition of the III-V compound. Time-of-flight (TOF) mass spectra clearly demonstrate high yield selective gas phase ionization and removal of the group I element from the ablation plumes of a variety of I-III-V Zintl-phase compounds. A 308 nm laser pulse serves as the ablation source and a second laser (248 nm or 266 nm) is used for selective ionization of the ejected species. For a particular Zintl-phase compound, potassium indium antimonide, K... |
