Journal Article XAS EXAFS X-ray absorption fine structure gallium nitride silicon dioxide Auger electron yields Auger electrons K-shell absorption Research Support, Non-U.S. Gov't SiC–MOS X-ray absorption fine structure (XAFS) X-ray absorption spectroscopy XAFS carbon coating copper oxide density functional theory dopants energy analyzer extended X-ray absorption fine structure film thickness hard X-ray photoelectron spectroscopy (HAXPES) interface structure layered polysilane lithium-ion battery (LIB) magnesium partial electron yield silicon negative electrodes silicon nitride surface sensitivity