Space-and-time current spectroscopy of nanostructured selenium in the chrysotile asbestos matrix

The non-steady-state photoelectromotive force effect was experimentally studied in a semiconductor nanowire array, i.e., in a composite representing selenium in a chrysotile asbestos matrix. The sample was exposed to an oscillating interference pattern, and the material response was measured as an alternating electric current. The experiments were performed for two geometries in which the excited photocurrent was parallel or perpendicular to nanowires. The dependences of the signal amplitude on the phase modulation frequency, spatial frequency, light polarization, and temperature were obtained. The photoelectric parameters of the material were determined for the light wavelength $\lambda$ = 633 nm. The effect was theoretically analyzed for the semiconductor model with shallow traps, which allowed the explanation of the observed increase in the signal amplitude in the presence of additional phase modulation.