Heterostructure-based devices with enhanced humidity stability for H2 gas sensing applications in breath tests and portable batteries

Semiconducting metal oxide - based gas sensors exhibit outstanding sensitivity, although humidity in the analyte typically hampers precise measurements. In this work it was shown that a 5?6 nm thin Al2O3 nano-layer is particularly beneficial reducing interference due to of p-type conductivity copper oxide-based sensors. An effective approach from chemical solutions at 75 °C and thermal annealing 600 used grow nano-crystallite layers. The nano-layers were subsequently deposited on top by atomic layer deposition high-aspect-ratio regime °C. morphological, structural, chemical, vibrational, electronical sensor characteristics heterostructured layers have been studied. final nano-Al2O3/CuO heterostructure showed an increase response H2 140 %, while long-term stability low high relative observed. initial sensing varied only 10 % for CuO with post-thermal acting as barrier water vapor oxygen. A comparison nanocrystallite covered ALD 6 15 ultra-thin films demonstrates exceptional hydrogen (84 RH). Density functional theory-based calculations molecule spontaneously dissociates over formed Al2O3/CuO heterostructure, interacting strongly surface Al atoms, showing different behavior compared pristine (111) surface, where molecules are known form surface. present study thorough optimization technology properties coverage formation nano-materials improves during applications which important real-world applications, e.g. portable battery analysis, breath tests, along environmental, medicine, security, food safety diagnostic tests.