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Healing Ion-Implanted Semiconductors by Hybrid Microwave Annealing: Activation of Nitrogen-Implanted TiO<sub>2</sub>
No full textIn order to recover the damaged structure of a nitrogen-implanted TiO2 photoanode, hybrid microwave annealing (HMA) is proposed as an alternative postannealing process instead of conventional thermal annealing (CTA). Compared to CTA, HMA provides distinctive advantages: (i) facile transformation of the interstitial N-N states into substitutional N-Ti states, (ii) better preservation of the ion-implanted nitrogen in TiO2, and (iii) effective alleviation of lattice strain and reconstruction of the broken bonds. As a result, the HMA-activated photoanode improves the photocurrent density by a factor of similar to 3.2 from 0.29 to 0.93 mA cm(-2 )at 1.23 V-RHE and the incident photon-to-current conversion efficiency (IPCE) from similar to 2.9% to similar to 10.5% at 430 nm relative to those of the as-prepared N-I-TiO2 photoanode in photoelectrochemical water oxidation, which are much better than those of the CTA-activated photoanode (0.58 mA cm(-2) at 1.23 V-RHE and IPCE of 5.7% at 430 nm), especially in the visible light region >= 420 nm)
Decoupling of CVD-grown epitaxial graphene using NaCl intercalation
No full textThe structural and electronic properties of graphene grown on catalytic metal surfaces are significantly modified via graphene-substrate interaction. To minimize the influence of the metal substrate, a dielectric buffer layer can be introduced between the graphene and metal substrate. However, the catalytic synthesis of graphene limits the potential alternatives for buffer layers. The intercalation of atoms below the graphene layer is a promising method that does not require the chemical treatment of graphene or the substrate. In this study, the electronic and structural properties of single-layer graphene (SLG) on the Cu(111) substrate intercalated with ultrathin NaCl thin films were investigated using scanning tunnelling microscopy. The intercalation of the NaCl monolayer decoupled SLG from the metal substrate, thereby producing quasi-freestanding graphene
Protein Corona-Shielding and Redox-Degradable Mesoporous Organosilica Nanoparticles for Enhanced Drug Delivery
No full textNondestructive Photopatterning of Heavy-Metal-Free Quantum Dots
No full textElectroluminescence from quantum dots (QDs) is a suitable photon source for futuristic displays offering hyper-realistic images with free-form factors. Accordingly, a nondestructive and scalable process capable of rendering multicolored QD patterns on a scale of several micrometers needs to be established. Here, nondestructive direct photopatterning for heavy-metal-free QDs is reported using branched light-driven ligand crosslinkers (LiXers) containing multiple azide units. The branched LiXers effectively interlock QD films via photo-crosslinking native aliphatic QD surface ligands without compromising the intrinsic optoelectronic properties of QDs. Using branched LiXers with six sterically engineered azide units, RGB QD patterns are achieved on the micrometer scale. The photo-crosslinking process does not affect the photoluminescence and electroluminescence characteristics of QDs and extends the device lifetime. This nondestructive method can be readily adapted to industrial processes and make an immediate impact on display technologies, as it uses widely available photolithography facilities and high-quality heavy-metal-free QDs with aliphatic ligands
Small-sized electrostatic PM2.5 monitor with a quartz crystal microbalance for environmental measurement drones
No full textApplication of 2D IR to Study h-IAPP Aggregation and Perovskite Films
No full textSince two-dimensional infrared (2D IR) spectroscopy was introduced in 1998, 2D IR has rapidly developed and is being applied to various fields. A variety of experimental methods are used nowadays. The pump???probe (PP) and the heterodyned photon echo (HPE) methods are the most widely used among them. In terms of experimental difficulty, HPE has an advantage over PP. However, PP has a relatively lower signal-to-noise ratio than HPE. When both techniques are applied to samples producing strong scatterings, such as metal???organic frameworks (MOFs), protein aggregates, and perovskite films, the spectra are severely contaminated by the scattered light. In the PP method, this problem can be circumvented by phase cycling. However, in the HPE method, phase cycling does not function as effectively as in the PP method. This presentation demonstrates that the scattering problem in the HPE approach can be solved mechanically by introducing choppers or shutters without moving any translation stages.[1] This scatter-removing technique was applied to investigate a perovskite film with a very rough surface and hIAPP protein aggregation. The perovskite film was found to contain a tiny amount of dimethylformamide and H2O. Temperature-dependent study on hIAPP shows that the proteins are denatured at 4 ??C from ??-sheets to random coils and ??-turns