ENDRINO ARMENTEROS, JOSÉ LUIS
No
Appl. Sci.-Basel
Article
Científica
2
2
01/01/2026
2-s2.0-105045914774
Al-doped zinc oxide (AZO) thin films were deposited by RF magnetron sputtering using a simple doping approach: aluminum tape was placed directly on the ZnO target. The work focused on understanding how Al incorporation, annealing temperature, and annealing atmosphere affect the structural and electrical behavior of the films, particularly their baseline resistance for gas sensing applications. EDX measurements confirmed that increasing the Al-covered area on the target progressively increased the Al concentration in the deposited layers. XRD analysis showed that higher Al contents and stronger thermal treatments reduced crystallinity and promoted the formation of smaller crystallites. The electrical response changed markedly with both Al incorporation and thermal treatment. Pure ZnO films initially exhibited very high resistance, while annealing reduced it by several orders of magnitude. Further increasing the Al concentration improved conductivity due to the donor effect of Al in the ZnO lattice. Overall, the results show that RF sputtering and post-treatment strategies can provide broad control over the electrical resistance of ZnO-based thin films. This tunability makes AZO coatings attractive for adapting chemoresistive gas sensors to different sensing environments and operating regimes, and deposition and thermal treatment parameters determine the resistance range. © 2026 by the author.
Aluminum coatings; Aluminum oxide; Chemical detection; Chemical sensors; Gas engineering; Heat treatment; Magnetron sputtering; Oxide films; Semiconducting films; Semiconductor doping; Thin films; Zinc oxide; aluminum; zinc oxide; Al doped ZnO thin films; Al incorporation; Al-concentration; Al-doped zinc oxide; Doped zinc oxide thin films; Gas-sensors; Sensor platform; Thermal; X- ray diffractions; ZnO; Article; atmosphere; behavior; electric conductivity; electric resistance; energy dispersive X ray spectroscopy; engineering; introspection; nonhuman; parameters; room temperature; X ray diffraction; II-VI semiconductors; X ray diffraction