Photoelectron spectroscopy studies of microcrystalline/amorphous silicon interfaces

Abstract Hydrogenated microcrystalline silicon (μc-Si:H) films and microcrystalline/amorphous silicon heterojunctions have been studied using in situ X-ray photoelectron spectroscopy (XPS), ultra-violet photoelectron spectroscopy (UPS), total yield and constant final state (CFS) spectroscopy. We present XPS valence band spectroscopy as a new method of determining the near-surface (∼5 nm) crystallinity of microcrystalline films. The analysis of the CFS spectra allows the direct determination of the valence band discontinuity at the μc-Si:H/a-Si:H interface. The experimental ΔEV=300±30 meV is in agreement with results obtained using indirect methods.