Jin Pyo Hong

Since graphene, a single sheet of graphite, has all of its carbon atoms on the surface, its property is very sensitive to materials contacting the surface. Herein, we report novel Raman peaks observed in annealed graphene and elucidate their chemical origins by Raman spectroscopy and atomic force microscopy (AFM). Graphene annealed in oxygen-free atmosphere revealed very broad additional Raman peaks overlapping the D, G and 2D peaks of graphene itself. Based on the topographic confirmation by AF

Abstract Developing a means by which to compete with commonly used Si‐based memory devices represents an important challenge for the realization of future three‐dimensionally stacked crossbar‐array memory devices with multifunctionality. Therefore, oxide‐based resistance switching memory (ReRAM), with its associated phenomena of oxygen ion drifts under a bias, is becoming increasingly important for use in nanoscalable crossbar arrays with an ideal memory cell size due to its simple metal–insulat

p-type ZnO nanowires (NWs) based on a simple hydrothermal technique with a lithium dopant are demonstrated. It is demonstrated that Li substitution of Zn occurrs because of thermally induced migration due to post-annealing in the presence of oxygen. The stable formation of p-type ZnO:Li NWs is revealed using a NW field-effect transistor and a simple n-type ZnO thin film/p-type annealed ZnO:Li NW homojunction diode. Detailed facts of importance to specialist readers are published as ”Supporting I

Half-metallic Fe3O4 films were prepared at room temperature using a rf sputtering system specially integrated with an external rf source. Primary emphasis was placed on obtaining a large amount of active oxygen radicals through an external electrode for efficient deposition. The insertion of an external electrode was found to be critical for room temperature growth of Fe3O4 thin films. The structural and electrical properties gave shift and broadening effects to the Verwey temperature at various

Wearable fabric-based energy harvesters have continued to gain importance for use in portable consumer electronics as an ecofriendly energy source that is independently self-powered by various activities. Herein, we address the output features of highly flexible Ni-Cu fabric-based triboelectric nanogenerators (F-TENG) employing surface-embossed polydimethylsiloxane (SE-PDMS) layers, as a crucial approach for enhancing power generation. Such SE-PDMS configurations were achieved via control of the

Wearable 2D textile platforms are the subject of intense focus to promote the creation of outstanding added value for textile-based applications in consumer electronics, energy harvesting, and storage. In particular, 2D textile-based energy harvesters from the living environment of human motions exhibit insufficient geometry deformation and low current density, thereby providing low power generation. Therefore, a unique starting point in this work is the use of 1D conductive bundle yarn (1D CBY)

Herein, we address the ZnO SLNR p–n homojunctions as UV photodetectors <italic>via</italic> a multi-step solution based hydrothermal route. Li was selected for manipulation of conduction type in ZnO and p-type ZnO:Li SLNRs were systematically investigated for crystallographic and luminescence features.

Recent studies have demonstrated that copper (I) thiocyanate (CuSCN) has huge potential as a hole extraction material (HEM) for perovskite solar cells. Here, we used CuSCN as a HEM and analyzed its relationships with a methylammonium lead iodide (MAPbI₃) perovskite layer. The CuSCN dissolved in diethyl sulfide (DES) was spin-coated on the MAPbI₃ layer. For high-quality and dense CuSCN layers, post-annealing was carried out at various temperatures and times. However, the unw

The possible nature of the improved device stability is proposed by employing the formation of Al nanoparticles (NPs) on the back channel of a ZnO film and a partial Al atom (ion) impregnation process.