Recently, terahertz frequency range has become the subject of significant interest among researchers. It can be explained by the fact that many materials absorb this radiation, e.g. water. So that many organic tissues can be studied with this approach. Several researches confirm terahertz efficiency for medical diagnosis. Metals and semiconductors can absorb THz either. Due to that fact it can be used in security applications, engineering and imaging as well. It is also a practical tool for astronomers – space emits THz radiation a lot.
Still there is a problem – nowadays there is a lack of fast and sensitive detectors that can operate at room temperature without extra cooling. However, this problem can be solved. Thermoelectric (TE) materials based on bismuth and antimony can be the solution. This material is promising for thermoelectricity due to narrow band gap.
Extra pairs of charge carriers appear while TE material absorbs THz radiation. These charge carriers have enough energy for transition to conduction band. This process is very familiar to thermoelectric effect. That means, TE material with finest figure of merit is required.
Due to size effects, thin film structures of BiSb demonstrate lower lattice thermal conductivity. This can increase the effect. BiSb thin films can operate at room temperature, which means that such devices do not consume extra energy for cooling.
In this work the heating process of THz sensor based on BiSb thin film on mica substrate was simulated and analyzed by the means of finite element method (FEM).
|Affiliation of speaker||ITMO Univerity|
|Position of speaker||PhD student|
|Publication||Impact Factor journals|