Mobility of indium on the ZnO(0001) surface

Abstract

The mobility of indium on the Zn-polar (0001) surface of single crystal ZnO wafers was investigated using real-time x-ray photoelectron spectroscopy. A sudden transition in the wettability of the ZnO(0001) surface was observed at similar to 520 degrees C, with indium migrating from the (000 (1) over bar) underside of the wafer, around the non-polar (1 (1) over bar 00) and (11 (2) over bar0) sidewalls, to form a uniform self-organized (similar to 20 angstrom) adlayer. The In adlayer was oxidized, in agreement with the first principles calculations of Northrup and Neugebauer that In2O3 precipitation can only be avoided under a combination of In-rich and Zn-rich conditions. These findings suggest that unintentional In adlayers may form during the epitaxial growth of ZnO on indium-bonded substrates. (C) 2015 AIP Publishing LLC.publishersversionPeer reviewe

Influence of Atomic Hydrogen, Band Bending, and Defects in the Top Few Nanometers of Hydrothermally Prepared Zinc Oxide Nanorods

“…where Σ  = (kT/ q )ln( N C / n ) [34] is the energy difference between E F and the conduction band minimum ( E CBM ) in the bulk of the sample ( n is the bulk carrier concentration 2 × 10 17  cm −3 and N C is the conduction band effective density of states = 2.94 × 10 18  cm −3 for ZnO). Using these values, the Σ was found to be 0.064 eV and V sbb  = 0.51 eV.…”

Band Alignment and Enhanced Interfacial Conductivity Manipulated by Polarization in a Surfactant-Mediated Grown κ-Ga2O3/In2O3 Heterostructure

“…The segregation of Sn has been reported during Ga 2 O 3 growth and induces the stabilization of κ-phase Ga 2 O 3 . 9−13 Furthermore, the surfactant-mediated growth of GaN 23, 24 and ZnO 25 has been reported by indium incorporation, while indium adlayers were also found to facilitate the growth of (Al x Ga 1 − x ) 2 O 3 / Ga 2 O 3 with an improved surface morphology through a metalexchange catalytic effect. 26−30 Therefore, both tin and indium elements act as surfactants during the Ga 2 O 3 growth and support a catalytic cycle according to the following reaction 31…”

“…Thermodynamic and kinetic factors both play significant roles in determining the growth mechanism. The segregation of Sn has been reported during Ga 2 O 3 growth and induces the stabilization of κ-phase Ga 2 O 3 . − Furthermore, the surfactant-mediated growth of GaN , and ZnO has been reported by indium incorporation, while indium adlayers were also found to facilitate the growth of (Al x Ga 1 – x ) 2 O 3 /Ga 2 O 3 with an improved surface morphology through a metal-exchange catalytic effect. − Therefore, both tin and indium elements act as surfactants during the Ga 2 O 3 growth and support a catalytic cycle according to the following reaction The negative values for Δ G 0 indicate a high probability for these reactions on the growing front. In other words, the thermodynamic influence of Sn and In surfactants can be expressed as a reduction of total energy of the growing surface.…”