Electrical properties of Si doped Ga2O3 films grown by pulsed laser deposition

In order to investigate Si doping effect on the structure and properties of Ga2O3 thin films, films with different Si content were grown by pulsed laser deposition (PLD) on sapphire substrates at 500 °C. Carrier density of 9.1 × 1019 cm−3 and conductivity of 2.0 S cm−1 have been observed for 1.1 at.% Si-doped film. Further increase of the Si content leads to the decrease of the carrier density. Atomic force microscope and spectrophotometer show that the obtained films have very smooth surface and high transmittance. X-ray diffraction reveals that films with Si content lower than 4.1 at.% are of high (-201) oriented monoclinic structure. Our work shows that PLD is ideal candidate for growing conductive Si-doped β-Ga2O3 films.