Media 1: Conductive optical-fiber STM probe for local excitation and collection of cathodoluminescence at semiconductor surfaces

Originally published in Optics Express on 12 August 2013 (oe-21-16-19261

Table1_Design-thinking skill enhancement in virtual reality: A literature study.docx

As a methodology, design thinking involves practicing “a way of thinking” that non-designers can use as a source of inspiration instead being limited to a group of professional designers. This methodology has gained research attention because of the growing demands for social innovation and sustainability. The general public is expected to gain design-thinking skills through training or by applying design-thinking tools. Virtual reality (VR) is considered a potential tool to help accelerate augmenting design-thinking skills because it allows users to have embodied and immersive experiences. This study reviews existing literature on how VR has been used to enhance design-thinking skills. The general features of the publications such as the year of publication, design-thinking stages, VR types, targeted participants, and publication fields are analyzed for determining the latest trends and scenarios under this research topic. Further, a thematic analysis that follows creative enhancement structures is conducted to understand the role of VR in enhancing design-thinking skills, and future research directions are discussed based on the results. The review concludes that VR has the potential to enhance creativity in many aspects. Moreover, it highlights the need of gaining deeper understanding about 1) art, humanities, and societal perspectives; 2) cognition processes in VR; 3) emphasizing and defining stages in the design-thinking process; 4) technological improvements combined with the Metaverse; and 5) hybrid of the virtual and real worlds.</p

Anchoring of Pt(II) Pyridyl Complex to Mesoporous Silica Materials: Enhanced Photoluminescence Emission at Room Temperature and Photooxidation Activity using Molecular Oxygen

Chloro(2,2′:6′,2′′-terpyridine)platinum(II) ([Pt(tpy)Cl]Cl) complex was successfully anchored to a series of (3-aminopropyl)trimethoxysilane-modified mesoporous silica materials (MCM-41, SBA-15, and MCM-48). Pt LIII-edge X-ray absorption fine structure (XAFS) measurements reveal that the Pt complex reacts with amino groups anchored on the mesoporous silica to create a new Pt−N bond. Upon anchoring, the nonemissive Pt(II) complex exhibits strong photoluminescence at room temperature, which is maximized near 530 nm due to ligand-centered (3LC) and/or metal-to-ligand charge transfer (3MLCT) transitions. The intensities of the emission increase in the order of MCM-41 3MMLCT) transition at high Pt loading. These results correspond well with the photocatalytic activities in the selective oxidation of styrene derivatives using molecular oxygen (O2). It can be supposed that the enhanced excitation rate and quantum efficiency of the anchored Pt complex, due to the differences in nanoconfinement, increase the energy and/or electron transfer to O2, which ultimately enhances the photooxidation activity. The 3D-connected channel structure of the MCM-48 silica also accounts for the high photocatalytic activity, where the diffusion of O2 toward the anchored Pt complex occurs smoothly compared to the one-dimensional MCM-41 and SBA-15 silicas, as demonstrated by the quenching rate constants obtained from Stern−Volmer plots

Ultrastable Silicon Anode by Three-Dimensional Nanoarchitecture Design

State-of-the-art carbonaceous anodes are approaching their achievable performance limit in Li-ion batteries (LIBs). Silicon has been recognized as one of the most promising anodes for next-generation LIBs because of its advantageous specific capacity and secure working potential. However, the practical implementation of silicon anodes needs to overcome the challenges of substantial volume changes, intrinsic low conductivity, and unstable solid electrolyte interphase (SEI) films. Here, we report an inventive design of a sandwich N-doped graphene@Si@hybrid silicate anode with bicontinuous porous nanoarchitecture, which is expected to simultaneously conquer all these critical issues. In the ingeniously designed hybrid Si anode, the nanoporous N-doped graphene acts as a flexible and conductive support and the amorphous hybrid silicate coating enhances the robustness and suppleness of the electrode and facilitates the formation of stable SEI films. This binder-free and stackable hybrid electrode achieves excellent rate capability and cycling performance (817 mAh/g at 5 C for 10 000 cycles). Paired with LiFePO4 cathodes, more than 100 stable cycles can be readily realized in full batteries

Band-Gap Deformation Potential and Elasticity Limit of Semiconductor Free-Standing Nanorods Characterized <i>in Situ</i> by Scanning Electron Microscope–Cathodoluminescence Nanospectroscopy

Modern field-effect transistors or laser diodes take advantages of band-edge structures engineered by large uniaxial strain ε_<i>zz</i>, available up to an elasticity limit at a rate of band-gap deformation potential <i>a</i>_<i>zz</i> (= d<i>E</i>_g/dε_<i>zz</i>). However, contrary to <i>a</i>_P values under hydrostatic pressure, there is no quantitative consensus on <i>a</i>_<i>zz</i> values under uniaxial tensile, compressive, and bending stress. This makes band-edge engineering inefficient. Here we propose SEM–cathodoluminescence nanospectroscopy under <i>in situ</i> nanomanipulation (Nanoprobe-CL). An apex of a <i>c</i>-axis-oriented free-standing ZnO nanorod (NR) is deflected by point-loading of bending stress, where local uniaxial strain (ε_<i>cc</i> = <i>r</i>/<i>R</i>) and its gradient across a NR (d<i>ε</i>_<i>cc</i>/d<i>r</i> = <i>R</i>^–1) are controlled by a NR local curvature (<i>R</i>^–1). The NR elasticity limit is evaluated sequentially (ε_<i>cc</i> = 0.04) from SEM observation of a NR bending deformation cycle. An electron beam is focused on several spots crossing a bent NR, and at each spot the local <i>E</i>_g is evaluated from near-band-edge CL emission energy. Uniaxial <i>a</i>_<i>cc</i> (= d<i>E</i>_g/dε_<i>cc</i>) is evaluated at regulated surface depth, and the impact of <i>R</i>^–1 on observed <i>a</i>_<i>cc</i> is investigated. The <i>a</i>_<i>cc</i> converges with −1.7 eV to the <i>R</i>^–1 = 0 limit, whereas it quenches with increasing <i>R</i>^–1, which is attributed to free-exciton drift under transversal band-gap gradient. Surface-sensitive CL measurements suggest that a discrepancy from bulk <i>a</i>_<i>cc</i> = −4 eV may originate from strain relaxation at the side surface under uniaxial stress. The nanoprobe-CL technique reveals an <i>E</i>_g(ε_<i>ij</i>) response to specific strain tensor ε_<i>ij</i> (<i>i</i>, <i>j</i> = <i>x</i>, <i>y</i>, <i>z</i>) and strain-gradient effects on a minority carrier population, enabling simulations and strain-dependent measurements of nanodevices with various structures

Metamorphic GaAs/GaAsBi Heterostructured Nanowires

GaAs/GaAsBi coaxial multishell nanowires were grown by molecular beam epitaxy. Introducing Bi results in a characteristic nanowire surface morphology with strong roughening. Elemental mappings clearly show the formation of the GaAsBi shell with inhomogeneous Bi distributions within the layer surrounded by the outermost GaAs, having a strong structural disorder at the wire surface. The nanowire exhibits a predominantly ZB structure from the bottom to the middle part. The polytipic WZ structure creates denser twin defects in the upper part than in the bottom and middle parts of the nanowire. We observe room temperature cathodoluminescence from the GaAsBi nanowires with a broad spectral line shape between 1.1 and 1.5 eV, accompanied by multiple peaks. A distinct energy peak at 1.24 eV agrees well with the energy of the reduced GaAsBi alloy band gap by the introduction of 2% Bi. The existence of localized states energetically and spatially dispersed throughout the NW are indicated from the low temperature cathodoluminescence spectra and images, resulting in the observed luminescence spectra characterized by large line widths at low temperatures as well as by the appearance of multiple peaks at high temperatures and for high excitation powers

Ultrastable Silicon Anode by Three-Dimensional Nanoarchitecture Design

State-of-the-art carbonaceous anodes are approaching their achievable performance limit in Li-ion batteries (LIBs). Silicon has been recognized as one of the most promising anodes for next-generation LIBs because of its advantageous specific capacity and secure working potential. However, the practical implementation of silicon anodes needs to overcome the challenges of substantial volume changes, intrinsic low conductivity, and unstable solid electrolyte interphase (SEI) films. Here, we report an inventive design of a sandwich N-doped graphene@Si@hybrid silicate anode with bicontinuous porous nanoarchitecture, which is expected to simultaneously conquer all these critical issues. In the ingeniously designed hybrid Si anode, the nanoporous N-doped graphene acts as a flexible and conductive support and the amorphous hybrid silicate coating enhances the robustness and suppleness of the electrode and facilitates the formation of stable SEI films. This binder-free and stackable hybrid electrode achieves excellent rate capability and cycling performance (817 mAh/g at 5 C for 10 000 cycles). Paired with LiFePO4 cathodes, more than 100 stable cycles can be readily realized in full batteries

Three-Dimensional Nanoporous Co₉S₄P₄ Pentlandite as a Bifunctional Electrocatalyst for Overall Neutral Water Splitting

Significant progress has recently been achieved in developing noble-metal-free catalysts for electrochemical water splitting in acidic and alkaline electrolytes. However, high-performance bifunctional catalysts toward both hydrogen evolution and oxygen oxidation reactions of neutral water have not been realized in spite of the technical importance for electrochemical hydrogen production in natural environments powered by renewable energy sources of wind, solar, and so on. Here, we report a nanoporous Co9S4P4 pentlandite with three-dimensional bicontinuous nanoporosity for electrochemical water splitting in neutral solutions. The three-dimensional binder-free catalyst shows a negligible onset overpotential, low Tafel slope, and excellent poisoning tolerance for hydrogen evolution reaction, comparable to or even better than commercial Pt catalysts. Remarkably, the new catalyst also has excellent catalytic activities toward oxygen evolution and, hence, can be used as both anode and cathode for overall neutral water splitting. These extraordinary catalytic activities toward neutral water splitting have never been obtained from non-noble-metal catalysts before. The bifunctional and low-cost catalyst holds great promise for practical applications in electrochemical water splitting in natural environments

Additional file 6 of Comparison of two protocols for steroid pulse therapy in patients with IgA nephropathy: a retrospective observational study

Additional file 6: Supplementary Figure 6. Stratified analysis for the remission rate of hematuria according to the histological grade during the study period