title: Evolution of microstructure and related optical properties of ZnO grown by atomic layer deposition.
abstract: A study of transmittance and photoluminescence spectra on the growth of oxygen-rich ultra-thin ZnO films prepared by atomic layer deposition is reported. The structural transition from an amorphous to a polycrystalline state is observed upon increasing the thickness. The unusual behavior of the energy gap with thickness reflected by optical properties is attributed to the improvement of the crystalline structure resulting from a decreasing concentration of point defects at the growth of grains. The spectra of UV and visible photoluminescence emissions correspond to transitions near the band-edge and defect-related transitions. Additional emissions were observed from band-tail states near the edge. A high oxygen ratio and variable optical properties could be attractive for an application of atomic layer deposition (ALD) deposited ultrathin ZnO films in optical sensors and biosensors.
authors.affiliation: European institute of membranes (IEM, ENSCM-UM2-CNRS, UMR 5635), University of Montpellier 2, Place Eugène Bataillon, F-34095, Montpellier, France.
authors.forename: Adib
authors.initials: A
authors.lastname: Abou Chaaya
authors.forename: Roman
authors.initials: R
authors.lastname: Viter
authors.forename: Mikhael
authors.initials: M
authors.lastname: Bechelany
authors.forename: Zanda
authors.initials: Z
authors.lastname: Alute
authors.forename: Donats
authors.initials: D
authors.lastname: Erts
authors.forename: Anastasiya
authors.initials: A
authors.lastname: Zalesskaya
authors.forename: Kristaps
authors.initials: K
authors.lastname: Kovalevskis
authors.forename: Vincent
authors.initials: V
authors.lastname: Rouessac
authors.forename: Valentyn
authors.initials: V
authors.lastname: Smyntyna
authors.forename: Philippe
authors.initials: P
authors.lastname: Miele
keywords: ZnO; atomic layer deposition; optical properties; photoluminescence; thin films