Quantitative analysis of trace elements in technological materials using online-laser ablation of solids in liquids (online-LASIL)

Abstract

To overcome the challenges of the 21st century, the demand for novel materials which outperforms the limits of previous material classes is high. However, the elemental composition determines crucial material properties from the bulk stoichiometry down to ultra-trace impurities. Therefore, a precise analytical characterization is inevitable to establish a connection between composition and function. For this purpose, conventional solid sampling techniques could be applied. However, matrix-matched standards are indispensable for quantitative analysis and are often unavailable in the case of technological materials. To overcome this limitation online-Laser Ablation of Solids in Liquids (online-LASIL) has been proposed recently, which combines the advantages of solution-based analysis and solid sampling techniques. However, this technique has only been applied to determine sample stoichiometry. In this work, major improvements of the online-LASIL approach were reported by the controllable segmentation of the carrier solution, leading to an improved washout behavior of the ablated material, enabling the quantitative investigation at trace levels. The accuracy of this improved measurement setup is validated by the quantitative analysis of trace elements in the standard reference material (SRM) NIST612. To demonstrate the applicability of this method, silicon carbide (SiC), a wide bandgap semiconductor, was analyzed. With the improved online-LASIL method, an Al-doped region, which is only constant for the first 250 nm, was successfully quantified.