Oscillating transient currents in PbSnTe:In in a backgroundless mode

Damping oscillations of a current are found in the PbSTe:In films after supplying a direct voltage to them in the absence of background illumination. A nonmonotonic transition to the steady state is discussed in the scope of the theory of the currents confined by a space charge upon the capture of electrons injected from the contacts to the traps distributed by energy, which leads to oscillating variation in polarizability and injection current. The ratio of the total current under the excitation by laser radiation with wavelength λ = 205 μm (hν = 0.006 eV) to the dark current could be larger or smaller than unity depending on the injection level of the electrons, i.e., supplied voltage, which can be interpreted in the scope of the suggested model.