Practical Electron Microscopy and Database

The built-in potential V_bi in the p-n junction in semiconductors can be measured by off-axis electron holography, given by,

          ------------------------------ [2552]
where,
          C_E -- A constant dependent on the energy of the electron wave (e.g. 7.29 x 10⁻³ rad V⁻¹ nm⁻¹ for 200 kV electrons),
          Δϕ -- The incident-electron phase change induced by the TEM specimen,
          t -- The local thickness of the specimen.

For detailed discussion, see page4305.