Authors: RP Doherty Yuekui Sun Ye Sun JL Warren NA Fox D Cherns MNR Ashfold
Publish Date: 2007/06/14
Volume: 89, Issue: 1, Pages: 49-55
Abstract
Growth of ZnO nanostructures on cplane sapphire has been investigated using three different methods Pulsed laser deposition PLD at low incident pulse energies can yield nanorods the majority of which are aligned at an angle of ∼50° to the substrate plane Selected area electron diffraction reveals that the nanorods display two distinct epitaxial relationships with the sapphire substrate Those inclined to the surface normal exhibit the relationships 112̄4ZnO//0001sap 101̄0ZnO//112̄0sap and 0001ZnO//101̄4sap 101̄0ZnO//112̄0sap Members of the second family are aligned along the surface normal with 0001ZnO//0001sap and 101̄0ZnO//112̄0sap the relative yield of this latter class increases at higher incident pulse energies Hydrothermal synthesis and chemical vapour deposition on sapphire substrates that have been precoated by PLD with a thin ZnO layer result respectively in wellaligned ZnO microrod and nanorod arrays both of which satisfy the relationships 0001ZnO//0001sap 101̄0ZnO//112̄0sap In contrast employing these latter methods with a bare sapphire substrate results in respectively poorly aligned structures and localized islands of growth
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