High-detectivity tin disulfide nanowire photodetectors with manipulation of localized ferroelectric polarization field

Tin sulfide semiconductor nanowires (NWs) have been widely investigated for photodetection applications because of their good optical and electrical properties. Herein, we synthesized n-type SnS2 NWs and then fabricated SnS2 NW photodetectors with a ferroelectric polymer side-gate. The strong electric field induced by ferroelectric polymer can effectively suppress the dark current and improve the detectivity in SnS2 NW photodetectors. The photodetectors after polarization depletion exhibit a high photoconductive gain of 4.0 × 105 and a high responsivity of 2.1 × 105 A W−1. Compared with devices without polarization depletion, the detectivity of polarization-depleted photodetectors is improved by at least two orders of magnitude, and the highest detectivity is 1.3 × 1016 Jones. Further, the rise and fall time are 56 and 91 ms respectively, which are about tens of times faster than those without polarization depletion. The device also shows a good spectral response from ultraviolet to near-infrared. This study demonstrates that ferroelectric materials can enhance optoelectronic properties of low-dimensional semiconductors for high-performance photodetectors.

Investigation of the phase delay of radiation by a transparent ferroelectric polymer film

In this paper, we study samples of an optically transparent ferroelectric polymer film with deposited nanoscale electrically conductive coatings designed to modulate the transmitted electromagnetic radiation of the visible and near-infrared wavelengths. Such films can be used, for example, in interference devices for phase delay compensation or for the implementation of the Phase Shifting Interferometry, in adaptive optics, etc. To measure the phase delay of the radiation passing through the samples under study, an installation based on the Mach-Zehnder interferometer was used. In the illumination branch of the installation, a broadband radiation source and an acousto-optic tunable filter are installed; in one of the arms of the interferometer, the test sample is installed. The interference pattern was recorded on a matrix radiation receiver; the phase information was decoded by digital holography methods. The report presents the results of measurements and shows that a modulation of the passed optical radiation occurs under the influence of the electric field as a result of changes in the geometrical dimensions of the film.