조용수 교수

Enhanced piezoelectric and energy-harvesting characteristics of Mn-doped (Na0.5K0.5)NbO3 (NKN) nanofibers have been investigated with actual fabrication of potential flexible nanogenerators. The electrospinning process of nanofibers has been initially optimized with the proper level of chelating agent and annealing temperature. High quality nanofibers are successfully obtained only by means of a certain level of doped-Mn, which incorporates into the NKN perovskite structure and facilitates signi

An enhanced conversion efficiency of ∼3.1% was achieved for non-colloidal PbS/CdS thin film solar cells with suitable band alignments.

This work reports the origin of high piezoelectricity of inorganic halide thin films poled at high fields along with the electromechanical energy-harvesting and motion-sensing performance.

Abstract Wearable pressure sensors having versatile device structures have been extensively investigated to achieve high sensitivity under mechanical stimuli. Here, we introduce piezoelectric pressure sensors based on fabrics woven using polyvinylidene fluoride (PVDF) weft and polyethylene terephthalate (PET) warp yarns with different weave structures: 1/1 (plain), 2/2, and 3/3 weft rib patterns. The dependence of the pressure-sensing performance on the weave pattern is demonstrated with an actu

A new potential low‐temperature co‐fired ceramics (LTCC) system based on a simple lanthanum borate (La 2 O 3 –B 2 O 3 ) glass was investigated with regard to phase development and microwave dielectric properties as functions of alumina filler content less than 50 wt% and firing temperature up to 1050°C. Unexpected crystalline phases, such as La(BO 2 ) 3 , LaAl 2.03 (B 4 O 10 )O 0.54 , LaBO 3 , and Al 20 B 4 O 36 , developed during the firing process are likely responsible for substantial resulta

Abstract Even though halide perovskite materials have been increasingly investigated as flexible devices, mechanical properties under flexible environments have rarely been reported on. Herein, a nonconventional deposition technique that can generate extra compressive or tensile stress in representative inorganic CsPbBr 3 and hybrid MAPbI 3 (methylammonium lead iodide) halide perovskites is proposed for higher mechanical flexibility. As an impressive result of bending fracture evaluation, fractu

A low temperature co‐fired ceramics system consisting of a typical calcium aluminoborosilicate glass and alumina filler was used to investigate the effects of four different sizes, 13 nm, 0.5, 3, and 39 μm, of a commercially available alumina filler on the resultant densification, crystallization, and dielectric properties. There was definitely a proper range of alumina particle size, which leads to desirable densification and enhanced dielectric properties. The onset temperatures of densificati

Very thin and highly transparent BiFeO₃ films are attractive owing to their potential application as ferroelectric photovoltaic devices.

The influences of processing parameters such as mineralizer, temperature, and nonstoichiometry on reaction product and morphology were investigated in the hydrothermal synthesis of yttrium iron garnet, Y 3 Fe 5 O 12 (YIG). A cubic YIG phase was synthesized successfully under hydrothermal conditions of 200°C and 6 h from yttrium and iron hydroxide coprecipitates obtained by adjusting the pH to 10.5 using NH 4 OH. The other mineralizer, NaOH, was not effective in forming the garnet phase. Nonstoic