Zinc oxide (ZnO) is a strong luminescent material, as are several polymers. These two materials have distinct drawbacks and advantages, and they can be combined to form nanostructures with many important applications, e.g., large-area white lighting. This paper discusses the origin of visible emission centers in ZnO nanorods grown with different approaches. White light emitting diodes (LEDs) were fabricated by combining n- ZnO nanorods and hollow nanotubes with different p-type materials to form heterojunctions. The p-type component of the hybrids includes p-SiC, p-GaN, and polymers. We conclude by analyzing the electroluminescence of the different light emitting diodes we fabricated. The observed optical, electrical, and electro-optical characteristics of these LEDs are discussed with an emphasis on the deep level centers that cause the emission.

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Luminescence from Zinc Oxide Nanostructures and Polymers and their Hybrid Devices

Vapor phase transport (VPT) assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn) was used to prepare un-doped and Al-doped zinc oxide (ZnO) nanostructures (NSs) The structure and morphology were characterized by field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD) Photoluminescence (PL) properties of un-doped and Al-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as zinc interstitials (Zni), oxygen interstitials (Oi), zinc vacancy (Vzn), singly charged zinc vacancy (VZn-), oxygen vacancy (Vo), singly charged oxygen vacancy (Vo+) and oxygen anti-site defects (OZn) in the grown NSs The Al-doped ZnO NSs have exhibited shifted PL peaks at near band edge (NBE) and red luminescence compared to the un-doped ZnO The Raman scattering results provided evidence of Al doping into the ZnO NSs due to peak shift from 145 cm-1 to an anomalous peak at 138 cm-1 Presence of enhanced Raman signal at around 274 and 743 cm-1 further confirmed Al in ZnO NSs The enhanced D and G band in all Al-doped ZnO NSs shows possible functionalization and doping process in ZnO NSs

/pdf/enhanced-photoluminescence-and-raman-properties-of-al-doped-3o5q6521rt.pdf

Enhanced photoluminescence and Raman properties of Al-Doped ZnO nanostructures prepared using thermal chemical vapor deposition of methanol assisted with heated brass.

Fluorescent hydrogels (FH) have a variety of potential applications in the field of soft electronics. However, fabrication of mechanically stable and printable fluorescent hydrogels remains challenging. Here, we report a kind of fluorescent hydrogel based on the co-assembly of peptide motif and transition metal ions. The metal ions are captured in the hydrogel network at specific positions through covalently linked ligands on the peptide hydrogelators. This efficiently prevents the aggregation and self-quenching of organometallic chromophores. In addition, the formation of metal-ligand complexes introduces additional interactions to stabilize the hydrogel network, making the FH even more stable after the incorporation of metal ions. The FH is optically transparent but highly fluorescent. By using three different metal ions, the white light fluorescent supramolecular hydrogel has been achieved. As a proof-of-principle, we demonstrate the printability of the hydrogels to various patterns. We anticipate that with the improved fluorescent performance and stability, this kind of FH can find broad applications in extrusion-based 3D printing for the construction of soft electronics.

Printable Fluorescent Hydrogels Based on Self-Assembling Peptides.

In this work, Ni-doped ZnO nanoparticles (NPs) were successfully synthesized by sol-gel method. The as-synthesized nanoparticles were characterized to investigate their morphology, structure, purit...

Morphological and Optical Characterization of Sol-Gel Synthesized Ni-Doped ZnO Nanoparticles

We presented combinations of vapor phase transport (VPT) of mixture of methanol and acetone and thermal evaporation of brass (CuZn) which contain in-situ three stages in obtaining un-doped and Mn-doped zinc oxide (ZnO) nanostructures (NSs). The structure and morphology were characterized by energy dispersive X-ray analysis (EDAX), field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The role of Ar as feed gas and interaction between methanol and brass have been predicted based on work reported elsewhere. Photoluminescence (PL) properties of un-doped and Mn-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as zinc interstitials (Zni), oxygen interstitials (Oi), zinc vacancy (VZn), singly charged zinc vacancy (V − ), oxygen vacancy (Vo), singly charged oxygen vacancy (V +) and oxygen antisite defects (OZn) in the grown NS. The Mn-doped ZnO NSs have exhibited shifted PL peaks compared to the un-doped ZnO.

C. Czekalla

Papers

Zinc Oxide Nanorod Based Photonic Devices: Recent Progress in Growth, Light Emitting Diodes and Lasers