The growth of Al-doped ZnO nanorods on c-axis sapphire by pulsed laser deposition

• Published in: Surface & coatings technology 2011-08, Vol.205 (21), p.5083-5087
• Main Authors: Kumarakuru, Haridas, Cherns, David, Fuge, Gareth M.
• Format: Article
• Language: English
• Subjects: Al-doped ZnO; Aluminum; Applied sciences; Arrays; Cross-disciplinary physics: materials science; rheology; Density; Electrical resistivity; Exact sciences and technology; Lasers; Materials science; Metals. Metallurgy; Nanorods; Physics; Production techniques; Pulsed laser deposition; Pulsed laser deposition (PLD); Scanning electron microscopy; Surface treatment; Surface treatments; Transmission electron microscopy; Zinc oxide; ZnO nanorods
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2011.05.011

Transmission and scanning electron microscopy are used to compare the growth of nanorod arrays in ZnO and Al-doped ZnO (2%Al) films grown by pulsed laser deposition. For a laser pulse energy of 10 mJ/pulse, nanorod arrays were formed at temperatures 575–625 °C for ZnO films and 650–675 °C for Al-doped ZnO films. For higher laser pulse energies, up to 30 mJ/pulse, nanorod growth in both cases moved to lower temperature regimes. By comparing nanorod growth temperature, morphology and density for ZnO and Al-doped ZnO growth, it is concluded that the differences in growth are due to lower surface diffusion rates in Al-doped films. The electrical resistivities of the Al doped ZnO films were in the range 5–7 × 10 − 3 Ω∙cm. ► Pure ZnO and Al-doped ZnO (AZO) nanorods can be grown by pulsed laser deposition. ► AZO nanorods grow at a higher temperature compared to ZnO at a given laser energy. ► For higher laser energy, growth in both cases moved into lower temperature regimes. ► The differences can be explained by lower surface diffusion rates in AZO. ► The electrical resistivities of AZO films were in the range 5–7 × 10 − 3 Ω∙cm.