Growth and characterization of well-aligned densely-packed rutile TiO(2) nanocrystals on sapphire substrates via metal-organic chemical vapor deposition

C A Chen; Y M Chen; A Korotcov; Y S Huang; D S Tsai; K K Tiong

doi:10.1088/0957-4484/19/7/075611

Growth and characterization of well-aligned densely-packed rutile TiO(2) nanocrystals on sapphire substrates via metal-organic chemical vapor deposition

Nanotechnology. 2008 Feb 20;19(7):075611. doi: 10.1088/0957-4484/19/7/075611. Epub 2008 Jan 31.

Authors

C A Chen¹, Y M Chen, A Korotcov, Y S Huang, D S Tsai, K K Tiong

Affiliation

¹ Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.

PMID: 21817648
DOI: 10.1088/0957-4484/19/7/075611

Abstract

Well-aligned densely-packed rutile TiO(2) nanocrystals (NCs) have been grown on sapphire (SA) (100) and (012) substrates via metal-organic chemical vapor deposition (MOCVD), using titanium-tetraisopropoxide (TTIP, Ti(OC(3)H(7))(4)) as a source reagent. The surface morphology as well as structural and spectroscopic properties of the as-deposited NCs were characterized using field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected-area electron diffractometry (SAED), x-ray diffraction (XRD) and micro-Raman spectroscopy. FESEM micrographs reveal that vertically aligned NCs were grown on SA(100), whereas the NCs on the SA(012) were grown with a tilt angle of ∼33° from the normal to substrates. TEM and SAED measurements showed that the TiO(2) NCs on SA(100) with square cross section have their long axis directed along the [001] direction. The XRD results reveal TiO(2) NCs with either (002) orientation on SA(100) substrate or (101) orientation on SA(012) substrate. A strong substrate effect on the alignment of the growth of TiO(2) NCs has been demonstrated and the probable mechanism for the formation of these NCs has been discussed.