Theory of electrical instabilities of mixed electronic and thermal origin. II. Switching as a nucleation process

The dynamics of the switching process in amorphous semiconductors is analyzed using a previously described electrothermal model. Utilizing recent preswitching noise data as input, we calculate the switching delay time as a function of current in the low-overvoltage regime in the nucleation approximation. It is found that the present, basically macroscopic theory is incapable of explaining the observed phenomena. A full explanation of switching in amorphous semiconductors requires, therefore, a more detailed understanding of the underlying microscopic electronic processes.