Boron nitride nanotubes (BNNTs) decorated Pd-ternary alloy (Pd_63·2Ni_34·3Co_2.5) for H₂ sensing

The micro-electro-mechanical system (MEMS)-based field effect transistor (FET) sensor for hydrogen detection was fabricated by modifying the gate electrode with boron nitride nanotubes (BNNTs) decorated Pd-ternary alloy (Pd_63·2Ni_34·3Co_2.5) as a hydrogen sensing layer Electro-thermal properties of the micro-heater embedded under sensor membrane were analyzed by a finite element method (FEM) simulation. The structural and morphological properties of the gate electrode were studied by Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM). A variation in gate potential is observed due to the H₂ atmosphere that leads to the variation in the depletion region, therefore, changing the current in the channel (BNNTs decorated Pd-ternary alloy). The BNNTs-decorated Pd ternary alloy displayed high sensing response, fast response and recovery time for H₂ gas, low power consumption, long-term stability, and wide detection range from 1 to 5000 ppm H₂. The drain current of the H₂ FET sensor varied significantly at hydrogen gas exposure and increased with H₂ concentration. As proposed H₂ FET sensor can be utilized to the H₂ leak detection system for safe applications.