https://doi.org/10.15407/iopt.2019.54.126

Optoelectron. Semicond. Tech. 54, 126-133 (2019)

H.V. Dorozinska

SENSITIVITY SIMULATION OF SENSORS BASED ON SURFACE PLASMON RESONANCE PHENOMENON WITH ADDITIONAL UPPER NANOLAYER OF POLYTETRAFLUOROETHYLENE

The method of numerical simulation in the work demonstrates the prospects for the use of additional polytetrafluoroethylene overhead nanolayer (PTFE) to increase the sensitivity of devices based on the phenomenon of surface plasmon resonance. This shows the possibility of replacing a gold nanolayer on a silver nanolayer in case where both metal films form additional upper polytetrafluoroethylene nanolayer that protects against the aggressive action of the medium and the oxidation of the surface when the interaction of the substances studied and the metal nanolayer. Optimization of the thickness of metal nano layer, the results of which are used in the modeling of metrological characteristics for sensitive elements on a basis of gold and silver with additional upper PTFE nanolayer was provided. The shift of the minimum of the reflection characteristic from the radiation wavelength in the range from 530 to 1550 nm was determined for sensitive elements of sensors with a layer of silver, with a layer of gold and with additional upper layers of PTFE for both variants. At the beginning of the apparent radiation wavelength range, the difference between the minima of the reflectance characteristics for the PTFE-gold sensitive element is Δθmin = 10° in comparison with the PTFE-silver element, which allows to expand the dynamic measuring range of devices based on the phenomenon of surface plasmon resonance with a sensitive element with a silver nanolayer and PTFE. The use of silver film with additional PTFE layer provides a greater sensitivity of approximately 2 times on measuring the intensity of reflected light at a constant angle of incidence compared to PTFE and gold nanolayer. The results of theoretical modeling are consistent with the experimental results obtained in previous works and obtained for the first time. Therefore, the use of sensors based on the phenomenon of the surface plasmon resonance with additional upper nanolayer of polytetrafluoroethylene can be used to improve the determination of the optical characteristics of the investigated medium and the chemical inertness of the working surface of optical gas sensors.

Keywords: surface plasmon resonance, polytetrafluoroethylene, sensor, sensitivity.