Proceedings of International Conference on Applied Innovation in IT  ·  2026/06/12  ·  Vol. 14  ·  Issue 4  ·  pp. 563–571
Characterization and Comparative Analysis of Structural, Optical and Gas-Sensing Properties of Aluminum-Doped Titanium Dioxide Thin Films
Reem Sami Ali, Hiba Saad Rasheed, Huda Saadi Ali, Wathiq Ayoub Taha Al Ramdhan and Hassan Hadi Darwoysh
This study examined some physical characterizations of aluminum-doped TiO₂ (TiO₂:Al) nanostructured thin films. Films with 0%, 2%, and 4% Al were deposited via chemical spray pyrolysis (CSP). A polycrystalline tetragonal anatase phase with preferred orientation along the (101) plane was verified by X-ray diffraction. Al³⁺ incorporation enhanced crystallinity, increasing crystallite size from 17.52 nm to 32.38 nm while reducing dislocation density and lattice strain. Atomic force microscopy revealed uniform nanoscale grains, with both particle size and surface roughness decreasing as Al content increased, indicating dopant-induced modifications in nucleation and growth. UV-Vis spectroscopy showed moderate transparency and a reduction in the direct optical band gap from 3.44 eV for undoped TiO₂ to 3.32 eV for 4% Al-doped films, attributed to defect states introduced by Al doping. Higher Al concentration increased electrical resistance but decreased sensitivity in gas-sensing studies toward NO₂ at 140°C, most probably as a result of changed surface adsorption and reduced charge-carrier mobility. Overall, Al doping tunes structural and optical properties effectively, though optimizing the dopant concentration is essential to balance material enhancements with functional gas-sensing performance.
TiO₂ Al Doping CSP Nanostructured Thin Films Gas Sensing
References
  1. K. Nagaraj, S. Radha, C. G. Deepa, K. Raja, V. Umapathy, N. P. Badgujar, … and C. Uthra, “Photocatalytic advancements and applications of titanium dioxide (TiO₂): Progress in biomedical, environmental, and energy sustainability,” Next Research, vol. 2, no. 1, 100180, 2025.
  2. H. Nosrati and M. Heydari, “Titanium dioxide nanoparticles: a promising candidate for wound healing applications,” Burns & Trauma, vol. 13, tkae069, 2025.
  3. N. Parveen, S. A. Ansari, K. M. Alnahdi, H. H. Hammud, W. A. Aljamhi, M. W. Alam, … and W. Al Zoubi, “Eco-friendly synthesis and applications of graphene-titanium dioxide nanocomposites for pollutant degradation and energy storage,” J. Photochem. Photobiol. A: Chem., vol. 459, 116096, 2025.
  4. Y. Liu, D. Wang, J. Zhang, Y. Wang, X. Yu, J. Chen, … and Y. Takeoka, “Synthesis and UV-Curing Mechanism of High-Refractive-Index Transparent Nanocomposites Embedded with Surface-Engineered TiO2 Nanoparticles,” Composites Part B: Engineering, 113116, 2025.
  5. A. V. Khlyustova, A. V. Evdokimova, V. D. Shibaeva, and N. A. Sirotkin, “Photochromic properties of TiO2: doping effect,” Bull. Russ. Acad. Sci.: Phys., vol. 89, no. 10, pp. 1889-1895, 2025.
  6. Z. Zhang, Z. Ma, Z. Du, Y. Chen, Q. Zhang, H. Du, … and M. Zendehdel, “Self-Assembly in Thin-Film Photovoltaics: Advancing Energy Conversion through Tailored,” in Functional Nanostructures for Energy Conversion and Advanced Applications, p. 61, 2026.
  7. P. Ramu and D. Patil, “Titanium dioxide coating for biomedical,” in High-Performance Metallic Biomaterials: Surface Modification and Coating of Implants, vol. 15, p. 101, 2025.
  8. I. Abdallah, J. Zapata, G. Lahiner, B. Warot-Fonrose, J. Cure, Y. Chabal, … and C. Rossi, “Structure and chemical characterization at the atomic level of reactions in Al/CuO multilayers,” ACS Appl. Energy Mater., vol. 1, no. 4, pp. 1762-1770, 2018.
  9. W. Zhang, B. Yin, R. Shen, J. Ye, J. A. Thomas, and Y. Chao, “Significantly enhanced energy output from 3D ordered macroporous structured Fe2O3/Al nanothermite film,” ACS Appl. Mater. Interfaces, vol. 5, no. 2, pp. 239-242, 2013.
  10. R. Agravat, S. K. Patel, A. K. U, T. Saidani, and A. Armghan, “Design of Metamaterial Surface Plasmon Resonance Solar Absorber Design Based on MXene-TiO2-Al Material for Renewable Energy Applications,” Plasmonics, vol. 20, no. 10, pp. 8689-8705, 2025.
  11. M. M. Mutter, R. H. Jabbar, and A. I. Khudiar, “Synthesis and characterization of TiO2: Al thin films for bacteria resistance in the implanted dental,” J. Aust. Ceram. Soc., vol. 58, no. 1, pp. 145-149, 2022.
  12. Q. Zhang, B. L. Xiao, W. G. Wang, and Z. Y. Ma, “Reactive mechanism and mechanical properties of in situ composites fabricated from an Al-TiO2 system by friction stir processing,” Acta Mater., vol. 60, no. 20, pp. 7090-7103, 2012.
  13. T. Li, E. Al Olevsky, and M. A. Meyers, “The development of residual stresses in Ti6Al4V-Al3Ti metal-intermetallic laminate (MIL) composites,” Mater. Sci. Eng. A, vol. 473, no. 1-2, pp. 49-57, 2008.
  14. J. Qin, S. Zhang, Z. Ma, and B. Lu, “Interfacial characteristics and mechanical properties of TiAl4822/Ti6Al4V metal-intermetallic laminate composite prepared through vacuum hot pressing,” Materials, vol. 18, no. 4, 898, 2025.
  15. W. Cheng, X. Li, C. Han, Y. Liu, A. Xue, H. Dong, … and Y. Liu, “Room-Temperature Wearable Chemiresistor Based on a Flexible Inorganic Photoactive Anatase-Rutile TiO2/Yttria-Stabilized Zirconia Nanofiber Network,” ACS Sensors, vol. 10, no. 3, pp. 2125-2135, 2025.
  16. C. Zhang, T. Wang, G. Zhang, R. Gao, C. Gao, Z. Wang, and F. Xuan, “Rational Design and Fabrication of MEMS Gas Sensors With Long-Term Stability: A Comprehensive Review,” Adv. Sci., vol. 12, no. 39, e11555, 2025.
  17. A. M. Al Saleh, “A Review of the Synthesis, Structural, and Optical Properties of TiO2 Nanoparticles: Current State of the Art and Potential Applications,” Crystals, vol. 15, no. 11, 944, 2025.
  18. M. E. Morais, J. C. Z. Griz, R. Brackmann, R. D. C. da Rocha, and M. de Souza Sikora, “Hydrothermal tuning of anatase-brookite TiO₂ nanostructures: influence of synthesis parameters on surface charge, crystallite size, and photocatalytic activity,” Catal. Today, 115753, 2026.
  19. K. A. Devi, G. M. Reddy, M. Harsha, S. Sujith, S. P. Maradur, G. V. Shanbhag, and N. Nalajala, “Unravelling TiO2 phase-engineering for hydrogen (H2) gas sensor applications,” Mater. Sci. Eng. B, vol. 328, 119317, 2026.
  20. S. Singh, K. C. Stiwinter, J. P. Singh, and Y. Zhao, “Glancing Angle Deposition in Gas Sensing: Bridging Morphological Innovations and Sensor Performances,” Nanomaterials, vol. 15, no. 14, 1136, 2025.
  21. Y. Zhao, S. Guo, X. Feng, T. Xie, Z. He, and Y. Lin, “High-performance formaldehyde sensing of room-temperature UV-activated Mn-TiO2: Key effects of different crystal phase structures and Mn doping on carrier behavior and adsorption,” SSRN, [Online]. Available: https://ssrn.com/abstract=5702846.
  22. A. Trajcheva, P. Morales, J. Elgoyhen, and R. Tomovska, “Thiol-Functionalized TiO2 as Reactive Nanoadsorbents for Residual Monomer Removal from Waterborne Polymer Dispersions,” Ind. Eng. Chem. Res., 2026.
  23. H. H. Issa and B. A. Hasan, “Gas sensing characteristics of (TiO2)1−x(ZnO:MgO)x thin films doped and undoped with Au NPs for NO2 and H2S detection prepared by spray pyrolysis,” Appl. Phys. A, vol. 131, no. 12, 1026, 2025.
  24. M. K. Modhi and J. M. Rzaij, “Synthesis and characterization study of CuO thin film and CuO-CeO2 nanostructured composite using chemical spray pyrolysis,” in AIP Conf. Proc., vol. 2591, no. 1, p. 030066, 2023.
  25. A. A. Khadayeir, R. I. Jasim, S. H. Jumaah, N. F. Habubi, and S. S. Chiad, “Influence of substrate temperature on physical properties of nanostructured ZnS thin films,” Journal of Physics: Conference Series, vol. 1664, no. 1, 012009, 2020.
  26. M. A. Issa and K. A. Aadim, “Optical and structural characterization of ZnO:NiO nano composite prepared by pulsed laser deposition method,” J. Opt., vol. 54, pp. 2357-2362, 2025.
  27. M. B. Jumaa, T. H. Mubarak, and A. M. Mohammad, “Synthesis and characterization of spinel ferrite Co0.8Fe2.2O4 nanoparticle,” Journal of University of Anbar for Pure Science, vol. 15, no. 2, pp. 74-82, 2021.
  28. S. S. Chiad, H. A. Noor, O. M. Abdulmunem, N. F. Habubi, M. Jadan, and J. S. Addasi, “Optical and structural performance of nanostructured Te thin films by (CSP) with various thicknesses,” Journal of Ovonic Research, vol. 16, no. 1, pp. 35-40, 2020.
  29. S. Göktaş and G. Şahin, “Impact of different Cu sources on the structure, surface morphology, optical and photocatalytic characteristics of sol-gel derived CuO thin films,” Türk Doğa ve Fen Derg., vol. 14, no. 1, pp. 13-20, 2025.
  30. S. S. Chiad, A. S. Alkelaby, and K. S. Sharba, “Optical conduct of nanostructure Co3O4 rich highly doping Co3O4: Zn alloys,” Journal of Global Pharma Technology, vol. 11, no. 7, pp. 662-665, 2020.
  31. M. Tram, N. Nosidlak, M. M. Szindler, M. Szindler, K. Tokarczyk, P. Dulian, and J. Jaglarz, “Optical Studies of Al2O3:ZnO and Al2O3:TiO2 Bilayer Films in UV-VIS-NIR Spectral Range,” Appl. Sci., vol. 15, no. 24, 12870, 2025.
  32. S. H. Mohamed and A. A. Alhazime, “Suppressing photoluminescence and enhancing light absorption of TiO2 via using TiO2/TiN/TiO2 plasmonic multilayers for better solar harvesting,” J. Mater. Res. Technol., vol. 18, pp. 4470-4478, 2022.
  33. W. A. Aelawi, S. Alptekin, and M. H. Al-Timimi, “Structural, optical, and electrical properties of nanocrystalline CdS1−XCuSX thin films,” Indian Journal of Physics, vol. 97, no. 13, pp. 3949-3956, 2023.
  34. M. A. Issa and K. A. Aadim, “Influence Of Laser Energy On Structural And Optical Properties Of ZnO(x):NiO(1−x) Films Prepared By Pulse Laser Deposition,” J. Opt., 2024.
  35. M. I. El-Henawey, M. Kubas, A. H. Oraby, A. El-Shaer, M. Abdelfatah, and H. Y. Salah, “Investigating the influence of Al2O3 doping on TiO2 optoelectronic properties and charge separation efficiency,” Opt. Mater., vol. 156, 115955, 2024.
  36. M. M. Mohammed, A. Eid, M. N. El-Sheikh, O. A. Elkady, and A. Hassan, “Effect of CNTs addition on the Mechanical and Tribological Properties of Al-10 wt.% TiO₂ Nanocomposites Manufactured by Powder Metallurgy,” Egypt. J. Chem., 2025.
  37. M. A. Issa and K. A. Aadim, “Study the structural and optical properties of Zinc Oxide prepared by pulse laser deposition,” J. Opt., 2024.
  38. J. Leng, Y. Ding, M. Zhang, and J. Shen, “Effect of Indium Doping on the Photoelectric Properties of SnS Thin Films and SnS/TiO2 Heterojunctions,” Coatings, vol. 15, no. 8, 972, 2025.
  39. M. M. El-Desoky, M. E. Abd-Elrazek, A. M. Elseman, and I. Morad, “Facile planetary ball mill synthesis, structural, photoluminescence, linear, and nonlinear optical features of Erbium-doped TiO2 nanoparticles,” Appl. Phys. A, vol. 131, no. 5, 402, 2025.
  40. N. F. Habubi, K. H. Abass, S. S. Chiad, D. M. A. Latif, J. N. Nidhal, and A. I. Al Baidhany, “Dispersion parameters of polyvinyl alcohol films doped with Fe,” Journal of Physics: Conference Series, vol. 1003, no. 1, 012094, 2018.
  41. A. A. Kamil, N. A. Bakr, T. H. Mubarak, and J. Al-Zanqanawee, “Effect of Au and Ag nanoparticles addition on the morphological, structural and optical properties of ZnO thin films deposited by sol-gel method,” Journal of Ovonic Research, vol. 18, no. 3, pp. 431-442, 2022.
  42. G. C. Kaphle, R. P. Kharel, and B. P. Kafle, “Experimental and theoretical study on electronic and optical properties of TiO2 (anatase) bulk and Al doped thin film phases,” J. Lumbini Eng. College, vol. 5, no. 1, pp. 17-27, 2023.
  43. C. C. Hsu, K. W. Huang, U. Kumar, Y. W. Suen, C. Sivakumar, and M. S. Ho, “Al-engineered anatase/rutile TiO2 heterostructures for superior resistive switching,” Appl. Mater. Today, vol. 49, 103146, 2026.
  44. N. N. Jandow, N. F. Habubi, S. S. Chiad, I. A. Al-Baidhany, and M. A. Qaeed, “Annealing effects on band tail width, Urbach energy and optical parameters of Fe2O3:Ni thin films prepared by chemical spray pyrolysis technique,” International Journal of Nanoelectronics and Materials, vol. 12, no. 1, pp. 1-10, 2019.
  45. A. A. Kamil, N. A. Bakr, T. H. Mubarak, and J. Al-Zanqanawee, “Synthesis and study of the optical and structural properties of Au and Ag nanoparticles by pulsed laser ablation (PLAL) technique,” Digest Journal of Nanomaterials and Biostructures, vol. 16, no. 4, pp. 1219-1226, 2021.
  46. F. Yakuphanoglu and M. Arslan, “The fundamental absorption edge and optical constants of some charge transfer compounds,” Opt. Mater., vol. 27, no. 1, pp. 29-37, 2004.
  47. A. A. Khadayeir, E. S. Hassan, T. H. Mubarak, S. S. Chiad, N. F. Habubi, M. O. Dawood, and I. A. Al-Baidhany, “The effect of substrate temperature on the physical properties of copper oxide films,” Journal of Physics: Conference Series, vol. 1294, no. 2, 022009, 2019.
  48. M. I. Sayyed and S. Biradar, “Tuning optical properties and gamma-ray attenuation performance in PbO2-modified borosilicate glasses,” Ceram. Int., vol. 51, no. 19, pp. 29344-29353, 2025.
  49. S. S. Chiad, H. A. Noor, O. M. Abdulmunem, and N. F. Habubi, “Optical and structural properties of Ni-doped Co3O4 nanostructure thin films via CSPM,” Journal of Physics: Conference Series, vol. 1362, no. 1, 012115, 2019.
  50. Y. S. Song, B. Y. Kim, N. I. Cho, and D. Y. Lee, “Effect of Al doping on optical band gap energy of Al-TiO2 thin films,” J. Nanosci. Nanotechnol., vol. 15, no. 7, pp. 5228-5231, 2015.
  51. N. D. M. Said, M. Z. Sahdan, A. Ahmad, I. Senain, A. S. Bakri, S. A. Abdullah, and M. S. Rahim, “Effects of Al doping on structural, morphology, electrical and optical properties of TiO2 thin film,” in AIP Conf. Proc., vol. 1788, no. 1, p. 030130, 2017.
  52. A. S. Mohammed and O. A. Fahad, “Sensitivity enhancement for NO2 gas sensor based on Alq3:TiO2,” in AIP Conf. Proc., vol. 2372, no. 1, p. 040008, 2021.
  53. A. Yüce and B. Saruhan, “Al-doped TiO2 semiconductor gas sensor for NO2-detection at elevated temperatures,” Tagungsband, pp. 68-71, 2012.
  54. B. Saruhan, A. Yüce, Y. Gönüllü, and K. Kelm, “Effect of Al doping on NO2 gas sensing of TiO2 at elevated temperatures,” Sens. Actuators B Chem., vol. 187, pp. 586-597, 2013.
  55. N. Y. Ahmed, B. A. Bader, M. Y. Slewa, N. F. Habubi, and S. S. Chiad, “Effect of boron on structural, optical characterization of nanostructured Fe2O3 thin films,” NeuroQuantology, vol. 18, no. 6, pp. 55-60, 2020.
  56. T. Xie, N. Sullivan, K. Steffens, B. Wen, G. Liu, R. Debnath, … and A. Motayed, “UV-assisted room-temperature chemiresistive NO2 sensor based on TiO2 thin film,” J. Alloys Compd., vol. 653, pp. 255-259, 2015.
  57. R. Özmenteş and A. S. Hassanien, “Characterizations and optical discussions of thermally evaporated titanium dioxide thin films,” Journal of Optics, vol. 54, no. 3, pp. 1322-1340, 2025.
  58. W. Zhao, H. Jia, J. Qu, C. Yang, Y. Wang, J. Zhu, … and G. Liu, “Sol-gel synthesis of TiO2-SiO2 hybrid films with tunable refractive index for broadband antireflective coatings covering the visible range,” Journal of Sol-Gel Science and Technology, vol. 107, no. 1, pp. 105-121, 2023.


Proceedings of the International Conference on Applied Innovations in IT by Anhalt University of Applied Sciences is licensed under CC BY-SA 4.0
 ·  This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License

ICAIIT 2026
International Conference on Applied Innovation in IT
Navigation
Publisher
ISSN2199-8876
Location Anhalt University of Applied Sciences
Phone +49 (0) 3496 67 5611
Address Building 01, Room 425
Bernburger Str. 55
D-06366 Köthen, Germany
Open Access License

All works are licensed under the Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0), unless otherwise noted.

Published by ICAIIT in cooperation with Anhalt University of Applied Sciences.

© 2026 ICAIIT — International Conference on Applied Innovations in IT. Anhalt University of Applied Sciences, Köthen, Germany.
Visitors: site traffic counter