Interfacing Lanthanide Metal‐Organic Frameworks with ZnO Nanowires for Alternating Current Electroluminescence

Abstract

Alternating current electroluminescence (ACEL) devices are attractive candidates in cost‐effective lighting, sensing, and flexible displays due to their uniform luminescence, stable performance, and outstanding deformability. However, ACEL devices have suffered from limited options for the light‐emitting layer, which presents a significant constraint in the progress of utilizing ACEL. Herein, a new class of ACEL phosphors based on lanthanide metal‐organic frameworks (Ln‐MOFs) is devised. A synthesis of lanthanide‐benzenetricarboxylate (Ln‐BTC) thin film on a brass grid substrate seeded with ZnO nanowires (NWs) as anchors is developed. The as‐synthesized Ln‐BTC thin film is employed as the emissive layer and shows visible electroluminescence driven by alternating current (2.9 V µm−1, 1 kHz) for the first time. Mechanistic investigations reveal that the Ln‐based ACEL stems from impact excitation by accelerated electrons from ZnO NWs. Fine‐tuning of the ACEL color is also demonstrated by controlling the Ln‐MOF compositions and introducing an extra ZnS emitting layer. The advances in these optical materials expand the application of ACEL devices in anti‐counterfeiting.

Simultaneously Engineering Oxygen Defects and Heterojunction into Ho-Doped ZnO Nanoflowers for Enhancing n-Propanol Gas Detection

“…In the previous works of our group, an n -propanol gas sensor based on the LaFeO 3 /La 2 O 3 heterostructure exhibited a high response value of 4.3 toward 1 ppm n -propanol gas . From the aspect of element doping, the enhancement of gas-sensing performances, including response value − and stability, , through the doping of rare earth elements in metal oxides has been widely reported. − Meanwhile, ZnO, as an n-type semiconductor, finds diverse applications in catalysts, , nanogenerators, , electroluminescence, , and gas sensors. , Inspired by these advantages, a 5% La-ZnO film was prepared that demonstrated a higher response value (400%) to 500 ppm H 2 gas compared to pure ZnO (80%) . Zhao et al prepared Ce-doped ZnO nanowires, which were exposed to 100 ppm ethanol, and exhibited a higher response (25.3) than pure ZnO (7.4) .…”

“…18 From the aspect of element doping, the enhancement of gas-sensing performances, including response value 22−25 and stability, 26,27 through the doping of rare earth elements in metal oxides has been widely reported. 28−32 Meanwhile, ZnO, as an n-type semiconductor, finds diverse applications in catalysts, 33,34 nanogenerators, 35,36 electroluminescence, 37,38 and gas sensors. 37,38 Inspired by these advantages, a 5% La-ZnO film was prepared that demonstrated a higher response value (400%) to 500 ppm H 2 gas compared to pure ZnO (80%).…”

“…28−32 Meanwhile, ZnO, as an n-type semiconductor, finds diverse applications in catalysts, 33,34 nanogenerators, 35,36 electroluminescence, 37,38 and gas sensors. 37,38 Inspired by these advantages, a 5% La-ZnO film was prepared that demonstrated a higher response value (400%) to 500 ppm H 2 gas compared to pure ZnO (80%). 39 Zhao et al prepared Ce-doped ZnO nanowires, which were exposed to 100 ppm ethanol, and exhibited a higher response (25.3) than pure ZnO (7.4).…”

Cationic Europium–Organic Framework for Chromatographic Column Separation of Ionic Dyes and Stimuli-Responsive Chromic Properties

“…Metal–organic frameworks (MOFs) have developed extensively in recent years, attracting considerable attention as crystalline porous materials with unique structures that can be tailored and optimized for specific properties. − Recent advancements highlight that MOFs have evolved into an outstanding platform for the creation of intelligent and multifunctional materials, − particularly in the field of water purification, involving tasks such as the extraction and degradation of pollutants. − The treatment of anionic pollutants in aqueous systems poses a formidable challenge, primarily due to the high environmental mobility of these pollutants, as most naturally occurring minerals are either neutral or negatively charged.…”