Origin of the difference between the capacitance intercept voltage and the built-in potential

For a diode with an abrupt, constant doping profile, the difference between the built-in potential V/sub bi/ and capacitance intercept voltage V/sub int/ is shown to be at least 2(k/sub B/T/q). The difference lies in the fact that q*V/sub int/ is related to the work needed to create this space charge.<
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