Dae Ho Yoon

The effect of the doping configuration and concentration of nitrogen (N) and sulfur (S) on the electrochemical performance of 3 D N and S co-doped hole defect graphene hydrogel (NS-HGH) electrodes is investigated. Surprisingly, by introducing a hole defect on the graphene surface, the difference in the doping concentrations of N and S can be used to effectively modulate the electrochemical behavior of the NS-HGH. The hole defects provide a rapid ion diffusion path. Finally, we showed that the in

Potassium lithium niobate ( K 3 Li 2- X Nb 5+ X O 15+2 X : KLN) crystals are difficult to grow by conventional crystal growth methods because of the distinct change of composition. Using the micro pulling down ( µ-PD) method, crack-free and homogeneous KLN crystals with a length of 150 mm and diameters of 150, 300 and 500 µm have been grown successfully. The crystals show good structural quality, single-domain structure and an excellent second harmonic generation property. The red irradiation of

Nickel cobalt sulfide nanoparticles embedded in holey defect graphene hydrogel (HGH) that exhibit highly porous structures and uniform nickel cobalt sulfide nanoparticle sizes are successfully prepared by a facile solvothermal-hydrothermal method. As an electrode material for supercapacitors, the as-prepared NiCo₂ S₄ @HGH shows ultra-high specific capacitances of 1000 F g^-1 and 800 F g^-1 at 0.5 and 6 A g^-1 , respectively, owing to the outsta

We report highly efficient ethyl cellulose with CsPbBr₃ perovskite QD films for white light generation in LED application. Ethyl cellulose with CsPbBr₃ quantum dots is applied with Sr₂Si₅N₈ : Eu²⁺ red phosphor on an InGaN blue chip, achieving a highly efficient luminous efficacy of 67.93 lm W^-1 under 20 mA current.

PSS coating layer can suppress the undesirable side reactions between the carbon and electrolyte (and/or Li2O2), which causes enhanced Li-air cell cyclic performance.