RESUMO
In this work, a copper iodine module bearing a coordination polymer (CP) with a formula of [(Cu2I2)2Ce2(INA)6(DMF)3]·DMF (1, HINA = isonicotinic acid, DMF = N,N'-dimethyl formamide) is presented. The title compound features a three dimensional (3D) structure, in which the {Cu2I2} cluster and {Cu2I2}n chain modules are coordinated by N atoms from a pyridine ring in INA- ligands, while the Ce3+ ions are bridged by the carboxylic groups of INA- ligands. More importantly, compound 1 exhibits an uncommon red fluorescence (FL) with a single emission band maximized at 650 nm belonging to near infrared (NIR) luminescence. The temperature dependent FL measurement was applied to investigate the FL mechanism. Remarkably, 1 could be used as a FL sensor to cysteine and the nitro-bearing explosive molecule of trinitropheno (TNP) with high sensitivity, demonstrating its potential FL sensing applications for biothiol and explosive molecules.
RESUMO
Thermochromic phosphors are intriguing materials for realizing thermochromic behaviors of light-emitting diodes. Here a highly luminescent and stable thermochromic phosphor based on one-dimensional Cu4 I6 (4-dimethylamino-1-ethylpyridinium)2 is reported. This unique ionic copper-iodine chain-based hybrid exhibits near-unity photoluminescence efficiency owing to the through-space charge-transfer character of relevant electronic transitions. More importantly, an alternative mechanism of thermochromic phosphorescence was unraveled, supported by a first principles simulation of concerted copper atom migration in the copper-iodine chain. Furthermore, we successfully fabricate a bright thermochromic light-emitting diode using this Cu4 I6 (4-dimethylamino-1-ethylpyridinium)2 thermochromic phosphor. Our reported flexible ionic copper-iodine chain-based thermochromic luminescent material represents a new type of cost-effective functional phosphor.
RESUMO
Ultraviolet(UV) photodetectors(PDs) can monitor UV radiation, enabling it to be effective for many applications, such as communication, imaging and sensing. The rapid progress on portable and wearable optoelectronic devices places a great demand on self-powered PDs. However, high-performance self-powered PDs are still limited. Herein we display a transparent and self-powered PD based on a p-CuI/n-TiO2heterojunction, which exhibits a high on-off ratio (â¼104at 310 nm) and a fast response speed (rise time/decay time = 0.11 ms/0.72 ms) without bias. Moreover, the device shows an excellent UV-selective sensitivity as a solar-blind UV PD with a high UV/visible rejection ratio (R300 nm/R400 nm= 5.3 × 102), which can be ascribed to the wide bandgaps of CuI and TiO2. This work provides a feasible route for the construction of transparent, self-powered PDs based on p-n heterojunctions.
RESUMO
This work presents the synthesis and deposition of CuI and FeCu materials on copper substrates for dye-sensitized solar cell applications. FeCu is a metastable alloy of iron and copper powders and possesses good optical and intrinsic magnetic properties. Coupled with copper iodide as tandem layers, the deposition of these two materials was permutated over a pure copper substrate, characterized and then tested within a solar cell. The cell was sensitized with a natural dye extracted from a local desert plant (Calotropis Gigantea) and operated with an iodine/triiodide electrolyte. The results show that the best layer arrangement was Cu/FeCu/CuI, which gave an efficiency of around 0.763% (compared to 0.196% from reported cells in the literature using a natural sensitizer).