Semiconductor Nanomaterials and their Based Study of Physical Properties of Functional Composites

The article studies the optical properties of two-dimensional nanocrystals of semiconducting potassium selenium (GaSe) in the structure of the composite active layer of a device analogous to an organic-inorganic light-emitting diode under the influence of an external electric field. The prepared device is a thin dielectric composite with two-dimensional GaSe nanocrystals, enclosed between indium tin oxide (capacitor-type device) and glass plates. It was experimentally shown that when an external electric field is applied to two-dimensional GaSe nanocrystals placed inside a dielectric composite, the integral intensity of their photoluminescence decreases by 15% (0–90 kV/cm), then the intensity is restored when the field is reduced to 0 kV/cm. After the external effect is removed, an increase in the intensity by 5% compared to the initial state was observed. The obtained experimental results and modeling based on them allowed us to put forward a hypothesis that the external electric field prevents the long-term (on the order of several microseconds) trapping of one of the excited charge carriers, and as a result, the recombination of excitons occurs on the nanosecond time scale. The potential of the new scientific method for determining the elemental and structural composition of composites is confirmed by the qualitative results of microspectral analysis of functional composite layers of the dye.