Dresden 2017 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 41: Layer Properties: Electrical, Optical, and Mechanical Properties II

DS 41.7: Vortrag

Donnerstag, 23. März 2017, 16:30–16:45, CHE 91

Laser spectroscopic in-situ temperature measurements on surfaces — •Eugen Speiser and Norbert Esser — Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V, Department Berlin, Schwarzschildstraße 8, 12489 Berlin, Germany

Laser spectroscopic methods for investigations of surface optical properties often require high incident excitation power (in MW/cm² range) leading to considerable heating effects which distort the measurements results. In many cases the heat transfer from the surface is hindered by interface effects or unfavorable substrate characteristics (e.g. low heat conductivity). A precise sample temperature determination becomes an issue, since conventional methods are not able to deliver a local temperature within the laser spot. An evaluation of Stokes to anti-Stokes ratios in Raman spectroscopy is a well-established in-situ method for local temperature measurements. However its imitation regarding a low signal to noise ratio and necessity for instrument corrections makes it often unfeasible. We propose a new vibrational spectroscopy based method for in-situ temperature determination on surfaces minimizing these drawbacks by exploiting the low energy Stokes and anti- Stokes range in Raman spectra. As an example temperature measurements on (4×1) metallic In nanowires on Si(111) in the range between 50 K and 450 K will be shown.