Photoelectron escape depth in Bi2Sr2CaCu2O8+x
Photoelectron spectra of Sr and Ca shallow core levels in Bi2Sr2CaCu2O81, (Bi2212) single crystals exhibit a strong attenuation effect because the photoelectron escape depth is very short in this material. This results may have a strong impact on the interpretation of ARPES and STM spectra near the Fermi level since it suggests the electronic states of planes other than CuO play a role in both tun