Here 𝜆= Relativistic electron wavelength, E and E0 are the relativistic and rest mass of electron. The overall voltage V can be written as a sum of long-rang electrostatic potential and a constant, which is often referred to as the mean inner potential (MIP). The phase shift is equivalent to the amount of charge across the heterostructure. This charge can be divided into two categories: 1) Static charge 2) Dynamic charge. The static charge can be due to presence of defects and localized charge, which contributes to MIP . The MIP is also dictated by the crystal structure as well as overall electron density. Increased electron density from Phosphorus doping can increase the overall MIP and vice versa . Furthermore, the presence of impurities and/or interstitial dopants in epitaxially grown Si:P can also result in static charge in the heterostructure. A change in the MIP will change the overall mean phase difference from electron holography. The dynamic charge results in depletion layer across the Si:P+/Si:B-interface. This is due to diffusion of electrons across the interface resulting in the presence of an internal electric field, across the interface.