Effect of Zn doping on structural, morphological, optical and electrical properties of nebulized spray-deposited CdO thin films

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2018-08, Vol.124 (8), p.1-13, Article 561
• Main Authors: Anitha, M., Anitha, N., Saravanakumar, K., Kulandaisamy, I., Amalraj, L.
• Format: Article
• Language: English
• Subjects: Applied physics; Characterization and Evaluation of Materials; Condensed Matter Physics; Doping; Electrical properties; Electrical resistivity; Energy gap; Glass substrates; Machines; Manufacturing; Materials science; Metals; Morphology; Nanotechnology; Optical and Electronic Materials; Optical properties; Photoluminescence; Physics; Physics and Astronomy; Processes; Q factors; Spray pyrolysis; Surfaces and Interfaces; Thin Films; X-ray diffraction
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-018-1993-7

Transparent and conducting pure and Zn-doped CdO thin films (0, 1, 2, 3 and 4 at.% Zn) have been successfully deposited on glass substrates at optimized substrate temperature of 200 °C by spray pyrolysis technique using nebulizer. Structural, morphological, optical and electrical properties of pure and Zn-doped CdO thin films are studied in detail. X-ray diffraction study confirms that all the CdO thin films were polycrystalline in nature with major reflection alone (111) plane having a cubic structure. The high average grain size (345 nm—SEM) and low RMS (6.46 nm—AFM) values are obtained for 3 at.% Zn-doped CdO thin films. The optical band gap energy had increased from 2.49 to 2.57 eV as the function of doping concentration had increased from 1 to 3 at.% Zn and thereafter decreased for higher doping concentration. A strong green emission and slightly shifted for Zn-doping concentration of CdO thin films exhibited by photoluminescence spectra. The CdO bond vibration confirmed by FTIR and Raman analyzes. The resistivity value of un-doped CdO thin film is 1.06 × 10 −3 Ω cm and adding Zn-doped concentration, the resistivity consequently decreased to 6.2 × 10 −4 Ω cm for 3 at.% Zn-doped CdO thin films and then furthermore increased. A high-quality factor (7.07 × 10 −2 ) was obtained for 3 at.% Zn-doped CdO thin films.