FEM Simulation of Frequency-Selective Surface Based on Thermoelectric Bi-Sb Thin Films for THz Detection

Terahertz (THz) filters and detectors can find a wide application in such fields as: sensing, imaging, security systems, medicine, wireless connection, and detection of substances. Thermoelectric materials are promising basis for THz detectors’ development due to their sensitivity to the THz radiation, possibility to be heated under the THz radiation and produce voltage due to Seebeck effect. Thermoelectric thin films of Bi-Sb solid solutions are semimetals/semiconductors with the band gap comparable with THz energy and with high thermoelectric conversion efficiency at room temperature. Detecting film surface can be transformed into a periodic frequency selective surface (FSS) that can operate as a frequency filter and increases the absorption of THz radiation. We report for the first time about the simulation of THz detector based on thermoelectric Bi-Sb thin-filmed frequency-selective surface. We show that such structure can be both detector and frequency filter. Moreover, it was shown that FSS design increases not only a heating due to absorption but a temperature gradient in Bi-Sb film by two orders of magnitude in comparison with continuous films. Local temperature gradients can reach the values of the order of 100 K·mm−1. That opens new perspectives for thin-filmed thermoelectric detectors’ efficiency increase. Temperature difference formed due to THz radiation absorption can reach values on the order of 1 degree. Frequency-transient calculations show the power dependence of film temperature on time with characteristic saturation at times around several ms. That points to the perspective of reaching fast response times on such structures.

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Cycling Times of Thin-Film NiTi on Si

MRS Proceedings ◽

10.1557/proc-246-427 ◽

1991 ◽

Vol 246 ◽

Cited By ~ 6

Author(s):

A. Peter Jardine

Keyword(s):

Thin Film ◽

Thin Films ◽

Mechanical Properties ◽

Response Times ◽

Bulk Material ◽

Fast Response ◽

Promising Candidate ◽

Strain Measurements ◽

Micro Actuator ◽

Acoustic Velocities

AbstractThe thermo-mechanical properties of NiTi are well known for bulk material although its deposition and utilization as a thin film are still in their earliest stages. The deposition of thin-films of Shape Memory Effect NiTi onto Si(100) wafers offers several advantages over bulk NiTi, including fast response times and comparitively large transformation forces, and so is a promising candidate as a micro-actuator for MicroElectroMechanical (MEMS) systems as well as in strain measurements. The response time for a variety of NiTi layers were modelled under different boundary conditions and show response times similar to the acoustic velocities for one micron thick NiTi.

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FEM Simulation of THz Detector Based on Sb and Bi88Sb12 Thermoelectric Thin Films

Applied Sciences ◽

10.3390/app10061929 ◽

2020 ◽

Vol 10 (6) ◽

pp. 1929

Author(s):

Anastasiia S. Tukmakova ◽

Alexei V. Asach ◽

Anna V. Novotelnova ◽

Ivan L. Tkhorzhevskiy ◽

Natallya S. Kablukova ◽

...

Keyword(s):

Thin Films ◽

Radiation Power ◽

Radiation Detection ◽

Fem Simulation ◽

Thz Radiation ◽

Frequency Range ◽

Mica Substrate ◽

Substrate Properties ◽

Thz Detector ◽

Thermoelectric Thin Films

A terahertz (THz) detector based on thermoelectric thin films was simulated using the finite elements method. The thermoelectric circuit consisted of S b and B i 88 S b 12 150-nm films on the mica substrate. S b , B i 88 S b 12 , and mica-substrate properties have been measured experimentally in the THz frequency range. The model of electromagnetic heating was used in order to estimate possible heating of S b - B i 88 S b 12 contact. THz radiation power varied from 1 μ W to 50 mW, and frequency varied in the range from 0.3 to 0.5 THz. The calculations showed a temperature difference of up to 1 K, voltage up to 0.1 mV, and responsivity of several mVW − 1 . The results show that thin S b and B i − S b thermoelectric films can be used for THz radiation detection at room temperatures.

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Nanostructure of semiconductor quantum dots in a borosilicate glass matrix by complementary use of HREM and AEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176770 ◽

1990 ◽

Vol 48 (4) ◽

pp. 728-729

Author(s):

M.J. Kim ◽

L.C. Liu ◽

S.H. Risbud ◽

R.W. Carpenter

Keyword(s):

Quantum Dots ◽

Borosilicate Glass ◽

Glass Matrix ◽

Optical Switching ◽

Response Times ◽

Fast Response ◽

Processing Technique ◽

Internal Stresses ◽

Electron Hole ◽

Spatial Dimensions

When the size of a semiconductor is reduced by an appropriate materials processing technique to a dimension less than about twice the radius of an exciton in the bulk crystal, the band like structure of the semiconductor gives way to discrete molecular orbital electronic states. Clusters of semiconductors in a size regime lower than 2R {where R is the exciton Bohr radius; e.g. 3 nm for CdS and 7.3 nm for CdTe) are called Quantum Dots (QD) because they confine optically excited electron- hole pairs (excitons) in all three spatial dimensions. Structures based on QD are of great interest because of fast response times and non-linearity in optical switching applications.In this paper we report the first HREM analysis of the size and structure of CdTe and CdS QD formed by precipitation from a modified borosilicate glass matrix. The glass melts were quenched by pouring on brass plates, and then annealed to relieve internal stresses. QD precipitate particles were formed during subsequent "striking" heat treatments above the glass crystallization temperature, which was determined by differential thermal analysis.

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Compact and efficient gas diffusion electrodes based on nanoporous alumina membranes for microfuel cells and gas sensors

The Analyst ◽

10.1039/c9an01882d ◽

2020 ◽

Vol 145 (1) ◽

pp. 122-131 ◽

Cited By ~ 1

Author(s):

Wanda V. Fernandez ◽

Rocío T. Tosello ◽

José L. Fernández

Keyword(s):

Response Times ◽

Hydrogen Oxidation ◽

Fast Response ◽

Gas Diffusion ◽

Limiting Current ◽

Gas Diffusion Electrodes ◽

Nanoporous Alumina ◽

Alumina Membranes ◽

Current Densities ◽

Microfuel Cells

Gas diffusion electrodes based on nanoporous alumina membranes electrocatalyze hydrogen oxidation at high diffusion-limiting current densities with fast response times.

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