• Apostoluk, Aleksandra
• Cornier, Thibaut
• Masenelli, Bruno
• Théron, Christophe
• Zhang, Y.
• Neumann, Paul
• Vilquin, Bertrand
• Daniele, S.

Abstract

The diversity of applications in optoelectronics, solar cells, light emitting diodes (LEDs), sensors and catalysis, as well as medical diagnostics profits from unique and attractive properties of and metal oxide nanostructures. In the present communication we report the fabrication methods and the properties of the metallic oxide nanostructures for solar cell and white light emitting diode applications (WLEDs). Zinc oxide and gallium oxide are wide bandgap semiconductors (3,37 eV and 4,8 eV for ZnO and beta-Ga2O3, respectively) and their nanostructures are of increasing interest because they have a variety of intrinsic defects that produce light emission in the visible range without the introduction of additional critical elements (doping). As technological costs and environmental concerns such as the use of critical metals or the issue of recycling become decision parameters, industrial fabrication methods should be cheap and harmless to humans, aquatic and terrestrial organisms, and the environment. To develop the studied nanostructures, hydrolysis method was used to synthesize ZnO nanoparticles and the Physical Vapor Deposition (PVD) for the fabrication of alpha-Ga2O3 and beta-Ga2O3. The obtained materials were characterized using various techniques. The XRD data and scanning electron microscopy (SEM)confirm the presence of nanoparticles and alpha and beta-Ga2O3 phases. Raman spectroscopy confirms the presence of some disorder for both ZnO and Ga2O3, characteristic of the presence of the defects. We discuss the effects of the nanoparticle size, the morphology and the surface stabilization on the enhancement of the PL QY in case of the ZnO NPs and of the PVD conditions for alpha- and beta-Ga2O3 thin layers. The photoluminescent emission of the studied materials is also examined, in order to achieve a perfect control of the defect emission to increase its efficiency. This opens up the prospect of synthesizing phosphors without rare earth for white LEDs, solar cells and whose spectrum can be tuned to render warm or cold white light, by a fabrication process easy to implement industrially and with a low environmental impact.

Topics

• nanoparticle
• impedance spectroscopy
• surface
• phase
• scanning electron microscopy
• x-ray diffraction
• zinc
• semiconductor
• physical vapor deposition
• defect
• Raman spectroscopy
• Gallium