The period doubling route to chaos of the electrical conductivity in excited photoconductors

In the present report the generation of sinusoidal signals in a photoconductor subject only to dc excitations is considered. For this purpose the model of an n-type photosensitive semiconductor containing two localized levels in its energy gap is examined. For suitable constant illumination and constant applied electric field the semiconductor is exhibiting periodic or chaotic conductivity, if the two levels are sufficiently closed to each other. As the levels move apart the signal experiences the period doubling route to chaos.