The flat band potential for a Mott-Schottky (MS) system is defined as the potential at which the system is electrically neutral, meaning that there is no net charge on the semiconductor surface. It is determined by the Fermi level of the metal and the electron affinity of the semiconductor. The flat band potential is typically measured by applying a bias to the MS system, and measuring the resulting current flow. The value of the flat band potential can be used to determine the density of states (DOS) of the semiconductor and the electron injection process across the metal-semiconductor interface. The flat band potential can also be affected by the presence of impurities or defects in the semiconductor and by the doping level.