Electrostatic Boundary Conditions and (Electro)chemical Interface Stability

Interface stability is a key factor for stable operation of electronic and electrochemical devices. This contribution introduces an approach for the operando analysis of interfaces using photoelectron spectroscopy employing a solid oxide electrochemical cell. The combined chemical and electronic information provided by the experiment reveals that not only chemical but also electrostatic boundary conditions are essential for interface stability. The approach is demonstrated using (anti‐)ferroelectric (Pb,La)(Zr,Sn,Ti)O3 dielectrics. Operando X‐ray photoelectron spectroscopy of antiferroelectric capacitors in electrochemical cells operated inside the spectrometer at elevated temperature reveals a correlation between the Fermi energy at the interface and the chemical decomposition of the dielectric, indicating the importance of the electrostatic boundary condition for the stability of the interface.