Experimental determination of the derivative of the current–voltage characteristic of a nonlinear semiconductor structure using modulation Fourier analysis

The derivative of the nonlinear current–voltage characteristic of two antiparallel $p$–$n$ junctions is experimentally obtained by the method of modulation Fourier analysis. The derivative of the current–voltage characteristic is reconstructed using the current dependences of the first and higher voltage harmonics. The advantage of modulation Fourier analysis over numerical differentiation is experimentally validated for the first time. The applied technique has no limitations on the current modulation amplitude. Large amplitudes make it possible to identify the nature of the nonlinearity of the dependence under study and to determine the contribution of the nonlinear fraction against the background of significant linearity.