Modification of electrical properties of TiO₂ by continuous-wave ytterbium fiber laser irradiation

Abstract

Polycrystalline plate-like TiO₂ specimens were irradiated with a continuous-wave Yb-fiber laser, and the electrical properties of the modified layers were investigated. The irradiated part was modified in color and electrical properties when the laser power was set above a certain threshold. The color changed from white to black, and the electrical resistivity drastically decreased from an initial value of 3.3 × 10⁹ Ω cm to 1.9 Ω cm at 2.0 W. The Hall measurement showed that the modified layer was an n-type semiconductor, and the carrier concentration was 3.6 × 10¹⁷ cm⁻³ at 2.0 W.