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Wide‐bandgap zinc oxide (ZnO)‐based light‐emitting diodes (LEDs) have attracted considerable interest for application in solid‐state lighting; however, the absence of dependable high‐quality homojunction has impeded their progress. A p–n homojunction LED is fabricated in this study using arc discharge‐fabricated N‐doped ZnO nanoparticles (NPs) spin coated over a Ga‐doped ZnO thin film. The homojunction LEDs demonstrate pure ultraviolet (UV) emissions with a narrow linewidth even at elevated temperatures. The UV intensity initially increases as the injection current increases to the saturation limit with a change in the peak position, followed by a decrease at higher injection currents. A proportion of UV light is downconverted into visible light using phosphors. Furthermore, the mixing of phosphors and their application to UV‐LED results in white emission with high color rendering and superior optical stability. Notably, the visible spectral peaks do not discernibly change with variations in the operating current. These findings represent significant advancements in the development of stable p‐type ZnO nanostructures, leading to the development of cost‐effective photonic devices. [ABSTRACT FROM AUTHOR]

This paper proposes a design method of three-dimensional (3-D) Y-C separation filters for the NTSC signals. The 3-D spectral structure of the NTSC signals, together with some existing and previously proposed Y-C separation methods, are first reviewed to point out some drawbacks in these methods. Since the Y-C separation filter proposed in this paper consists of a horizontal one-dimensional (1-D) FIR filter and a temporal-vertical two-dimensional (2-D) nonseparable FIR filter, the design of the temporal-vertical 2-D nonseparable FIR filter is intensively discussed, which is more difficult to design than the 1-D one. The design procedure is simplified by applying some 2-D frequency transformations and then formulated as a simple linear programming problem, which can be solved easily by the standard method (e.g., the revised simplex method). Another advantage of our approach is the flexibility that enables us to design various shapes of the passband and the support of the impulse response. Two design examples are given to show the usefulness of our approach. A hardware implementation of the proposed filters is also considered., The design and realization of three-dimensional filters which fully separates interleaved luminance and chrominance signals fortelevision broadcasting is discussed. The proposed design is comprised of a one-dimensional finite impulse response (FIR) filter and a two-dimensional FIR filter and is derived through frequency transformations and a linear programming framework. Two examples are provided to demonstrate the proposed design's validity and efficacy.