Photoelektronenspektroskopie von mikrokristallinem Silizium

Hydrogenated microcrystalline silicon (#mu#c-Si:H) thin films and heterojunctions of microcrystalline/amorphous silicon have been studied using in-situ X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), total yield (TY) and constant final state (CFS) spectroscopy. The electronic density of states and the valence band discontinuity were examined in order to gain a deeper understanding of the electronic structure of microcrystalline silicon. High-resolution valence band spectroscopy was utilized to distinguish amorphous silicon from crystalline material. This gave birth to a new and promising method of determining the near-surface crystallinity of thin microcrystalline films. Furthermore, photoelectron yield spectroscopy provides a powerful tool for analysing heterostructures in the upper part of the valence band density of states. Due to its relatively large sampling depth and its high dynamical range both valence band edges can be identified. Thus the analysis of the TY/CFS spectra allowed the direct determination of the valence band discontinuity at the interface between microcrystalline and amorphous silicon. Being the classical methods to study band offsets, XPS and UPS were also applied to confirm the experimental results by analysing core level shifts. The experimental value of #DELTA#E = 0.3 eV is in excellent agreement with results obtained using indirect methods. (orig.)81 refs.Available from TIB Hannover: RA 831(3767) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman