University of Houston researchers have used single-crystal aluminum Nitride (AlN) substance as the basis of an electronic pressure sensor, which operates at temperatures of up to 90degC. AlN is defined as a material with a single crystal structure that is ideal in relation to applications for pressure sensing. Single-crystal aluminum nitride (AlN) is a chemical comprised of aluminium (Al) along with nitrogen (N) particles that are placed in an ordered lattice which provides better mechanical electrical, thermal, and mechanical properties when compared with polycrystalline materials. According to this article researchers have employed single-crystal AlN to create high-temperature pressure sensors with increased performance and sensitivity.
After their experience using single-crystalline gallium Nitride pressure sensors, which had sensitivity decreases at temperatures above 350degC. This team has also developed pressure sensors that are made from one crystals of gallium nitride, which show similar results.
Houston declared, “the team suspected the decrease in sensitivity was caused by bandgap not being wide enough. To test this theory, they constructed an aluminium nitride sensor.”
After overcome the technical difficulties encountered in synthesizing and manufacturing high-quality flexible thin-film AlN They succeeded in creating a device that has an “highest operating temperature among piezoelectric sensors” according Nam-In Kim, the researcher who developed the technology.
The output voltage of the sensor can vary between 73.3mV and up 143.2mV when detecting changes of pressures between 50psi to 200psi at 800degC.
Furthermore, a decrease of diaphragm Young’s modulus, as well as free carrier generation negatively affected the performance in a small way.
Researchers also created the polycrystalline AlN or single crystal GaN thin films to serve as a comparability measure.
AlN has excellent thermal, chemical and strength stability. Nuclear facilities can therefore be able to benefit by AlN sensors that operate in neutron-rich atmospheric conditions as per the team of researchers.