Regensburg 2013 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 19: Poster 2

DF 19.17: Poster

Wednesday, March 13, 2013, 15:00–17:30, Poster B2

Electrical and optical properties of tungsten doped VO₂ thin films — •Sebastian Vatterodt¹, Jura Rensberg¹, Danilo Buerger², Heidemarie Schmidt², and Carsten Ronning¹ — ¹Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany — ²Institut für Materialsysteme der Nanoelektronik, Technische Universität Chemnitz, 09107 Chemnitz, Germany

Single crystalline vanadium oxide (VO₂) undergoes a reversible metal to insulator transition (MIT) accompanied by a structural transition from metallic rutile phase (R) to insulating monoclinic phase (M1) at a temperature of about 68^∘C. Most likely, this transition is caused by electron-electron correlation which leads to a splitting of the V⁴⁺ 3d valence band. Therefore, a band gap with an energy of about 0.6 eV is observed in the insulating phase. Furthermore, it is well known that the transition temperature in VO₂ can be decreased by high valent dopants, i.e. tungsten, which are incorporated into the lattice. Here we investigated the influence of tungsten doping on the electronic structure. Thus we grew VO₂ thin films on sapphire by pulsed laser deposition (PLD) with different tungsten content. The films were characterized by measuring both their transmittance in the UV-VIS-NIR spectral range and their sheet resistivity as a function of the temperature. The changes of the electronic structure, i.e. the position of the V⁴⁺ 3d band, due to tungsten doping are discussed and compared with theoretical band structure calculations.