Cathodoluminescence of Single Disk-Like ZnO Prepared by Low Temperature Solution-Based Method

Abstract

Single crystalline ZnO disk-like structure with good luminescent properties was obtained by a low temperature solution based method. Micro-emulsion was employed to assist the shape control. The product has a perfect hexagonal shape with flat bottom and up surfaces, and has a wide size distribution, the size ranges from nano to micro-scale. Electron diffraction (ED) pattern coupled with transmission electron microscopy (TEM) indicate that the single disk was single-crystalline. In cathodoluminescence (CL) studies at room temperature for wavelengths between 350 and 675 nm, we have observed a single exciton peak around 390 nm without any deep-level emission. The monochromatic CL mapping in the ultra-violet (UV) region has such properties as: the intensity is concentrated along the boundary of the cavity; the emission is predominantly at the corner.

Exciton-Assisted UV Stimulated Emission with Incoherent Feedback in Polydisperse Crystalline ZnO Powder

“…In this case, adjacent modes spectrally overlap, which gives a continuous spectrum of emission. This result qualitatively differs from observations on the samples of the ZnO film with hexagonal microdisks formed by the method based on a low-temperature solution [20].…”

“…The samples were prepared in the form of three types of disordered ZnO media: polydisperse nano-micro-crystalline (PNMC) compressed ZnO powder, film-forming solutions, based one-component neutral-curing silicone sealant that cures at room temperature, and microcrystalline hexagonal plate-like films obtained by low-temperature hydrothermal method [20]. PNMC ZnO powder was "white seal", standard BZ0M, declared purity not less than 99.8%, crystal particle size range 50 nm -2 m, specific surface area 6-12 m 2 /g production of classical chemical and metallurgical French process in a high-temperature Welz furnace.…”

“…The samples of PNMC ZnO powder were prepared in the form of layers with a thickness of 50 microns sandwiched between quartz plates. For comparison, we also used data for a low-dispersed ZnO powder with nanoparticles (NPs) of an average size of 100 nm, as described in [20]. The experimental setup for laser optical spectroscopic measurements is shown in Figure 1.…”

Nanosized hexagonal plateletlike ZnO for nanophosphor applications

“…12 For the preparation of the ZnO nanoplatelets, hexamethylenetetramine ͑HMT͒ ͑C 6 H 12 N 4 ͒ is used as a precursor instead of ammonium. 12 For the preparation of the ZnO nanoplatelets, hexamethylenetetramine ͑HMT͒ ͑C 6 H 12 N 4 ͒ is used as a precursor instead of ammonium.…”

“…12 Here we focus on the temperature-dependent photoluminescence ͑PL͒ and yttrium aluminum garnet ͑YAG͒-laser-excited PL properties of the microsized ZnO platelet. 12 Here we focus on the temperature-dependent photoluminescence ͑PL͒ and yttrium aluminum garnet ͑YAG͒-laser-excited PL properties of the microsized ZnO platelet.…”