ZnO NANOCOMPOSITE FILMS MADE BY MULTI-BEAM MULTI-TARGET PULSED LASER DEPOSITION

Combining ZnO with various inorganic and organic constituents into nanocomposite films with various functionalities can be efficiently done with the method of concurrent pulsed laser ablation of multiple targets. A particular variation of the method that will be discussed in the chapter is the recently proposed concurrent multi-beam multi-target pulsed laser deposition and matrix assisted pulsed laser evaporation (CMBMTPLD/MAPLE). The focus will be on two types of nanocomposite films: (a) polymer films were aluminum-doped ZnO (AZO) nanoparticles enhance by the plasmonic amplification the infrared emission of other nanoparticles made of a rare-earth (RE) doped phosphor NaYF₄: Tm³⁺, Ho³⁺ and (b) wide-band nanocomposite epsilon-near-zero (ENZ) films made of metal-doped ZnO and other transparent conductive oxide (TCO) low loss alternatives to the traditional dielectric-metal metamaterials. The chapter discusses: (1) design of the open-air CMBMT-PLD/MAPLE system capable of making large area coatings; (2) deposition process; (3) micro-structure and morphology of the films; (4) functional properties of the films; (5) potential and future directions of the research and development of metal-doped ZnO nanocomposites towards wide-band ENZs; (6) conclusions. The following major results will be reported. (A) Adding AZO nanoparticles improved by a factor of 1.3 the intensity of infra-red emission from the polymer films with RE-phosphor due to the plasmon enhancement of the pump infrared radiation near the AZO nanoparticles. (B) Combining AZO and other metal-doped ZnO and TCO constituents was estimated to result in nanocomposite ENZs with a spectral band as wide as 100 nm. The information provided in the chapter will be useful for professionals working in the fields of material science, laser processing of materials, light emitters, and photonics.