Thin-films for Power Electronic Applications*

Electronic devices based on ultrawide band gap (UWBG) oxides are capable of handling high voltages. Recently, computational calculations have suggested that In₂Ge₂O₇ (IGO), an UWBG oxide, holds promise in power electronics. These calculations show IGO to have desirable properties, namely the capacity for n-type doping, single crystal epitaxial growth, and high thermal conductivity. Here, Zr-doped IGO thin films are deposited via pulsed laser deposition at substrate temperatures between 600-800℃. An optimal O₂ partial pressure of 250 mTorr was used to grow stoichiometric films of Zr-doped IGO. The structural, electrical, and optical properties are characterized by X-ray diffraction, Hall effect measurements, and spectroscopic ellipsometry, respectively. Optical and electrical characterization has confirmed Zr-doped IGO as an appropriate n-type semiconductor for power devices due to its measured band gap of ~3.9 eV and carrier concentration of ~2.5x10¹⁵ cm^-3. Structural characterization shows Zr-doped IGO thin-films to be polycrystalline or textured, with further optimization needed for epitaxial growth to be achieved. By understanding Zr-doped IGO, we present a new material that can be used in high voltage devices operable at high temperatures and capable of efficient power output for applications in electric vehicle motors, industrial machinery, and energy generation.