  We present a novel resistance-compensated I-V method to extract the series
resistance, ideality factor, barrier height and built-in potential of a
metal-semiconductor diode. We show that a reduced equation arises from a unique
but hitherto unreported symmetry in the Schottky equation when it is written as
an ordinary differential equation. In spite of the intense mathematical
justification, we show how this new equation is directly applicable to an
empirical data set through a simple algorithm. We test the method on a new
Al/p-Si/Bi$_2$Se$_3$/Al Schottky diode and compare it with the Cheung-Cheung
method on the same data. The series resistance was found to change
exponentially with applied bias with a rate constant that depends on the
incident illumination. The barrier height decreased with bias but was
independent of the incident illumination. The trends in the results of the
method agree strongly with the literature and may yield more accurate diode
parameters compared to other electrical methods.
