Raman spectroscopy and field emission characterization of delafossite CuFeO2

摘要: Delafossite p-type CuFeO2 (CFO) semiconductors were synthesized by a modified solid state reaction technique and investigated x-ray diffraction, photoemission spectroscopy (XPS), energy dispersive spectroscopy, scanning electron microscopy, revealing the single-phase nature of CFO with 1:1 Cu/Fe atomic ratio. The valance states examined XPS suggest Cu Fe ions are in +1 +3 high spin S=5/2. “turn-on field” which is macroscopic field needed to get an emission current 9 nA, was calculated as 5.72 V/μm. Room temperature Raman spectra displayed two main active modes at Eg∼351 cm−1 Ag∼692 cm−1 accord other delafossite structures. Temperature dependent showed that both shifted lower frequency significant decrease intensity increase temperature. Frequency shift linewidth phonon lines matched well theoretical damped harmonic oscillator model based on t...