To realize flexible and wearable electronic devices in the future, it is important to develop flexible transparent electrodes while replacing indium tin oxide‐based transparent electrodes. Herein, a highly conductive transparent electrode based on hybrid materials of MXene nanosheet films and Ag nanowires (AgNWs) is reported, which synergistically combines the advantageous properties of each material. MXene/AgNW/colorless polyimide (cPI) hybrid electrode is prepared utilizing reverse sequential processing of MXene nanosheets and AgNWs and exhibits significantly improved conductivity and transmittance compared with the MXene/cPI electrode. Furthermore, owing to the abundant hydrophilic termination groups (‐O and ‐OH) on the MXene surface, the MXene/AgNW/cPI hybrid electrode shows hydrophilic surface properties and a highly uniform film. Therefore, the MXene/AgNW/cPI hybrid electrode exhibits higher transmittance at 550 nm to 79% than MXene/cPI electrode (59%) and considerably lower sheet resistance (13.08 ohm sq −1 ) than MXene/cPI electrode (113.6 ohm sq −1 ). Flexible organic photovoltaic devices fabricated with MXene/AgNW/cPI hybrid electrode achieve higher power conversion efficiency of 10.3% compared with 6.70% of the corresponding MXene/cPI electrode. These results provide the great potential of Ti 3 C 2 ‐based MXene hybrid electrode as a flexible transparent electrode, paving the way for various and wider range of applications include solar cells and light‐emitting diodes.
타이타늄산바륨($BaTiO_3$)은 대표적인 강유전 물질로 유전상수가 200 이상의 값을 나타내는 물질이다. 타이타늄산바륨을 나노입자화하면 나노커패시터(nanocapacitors)와 강유전체 메모리(ferroelectric random access memories)와 같이 여러 용도로 응용 가능하다. 하지만, 나노입자의 합성방법에 따라 나노입자의 분산특성이 달라지며 이에 활용할 수 있는 분야가 달라질 수 있다. 본 연구에서는 타이타늄산바륨 나노입자를 옥살레이트법(oxalate method)과 sol-gel법(ambient condition sol method)으로 합성하고 각 방법에 따른 나노입자의 크기와 분산상태를 확인하였다. 각각의 공정에 사용한 캡핑 에이전트(capping agent)는 poly vinyl pyrrolidone (PVP)을 옥살레이트법에 이용하였고 sol-gel법에는 tetrabutylammonium hydroxide (TBAH)를 이용하였다. 합성된 나노입자의 X-선 회절 분석 패턴을 분석하여 cubic 결정구조를 갖는 타이타늄산바륨을 확인하였다. 푸리에(Fourier) 변환 적외선 분광분석을 이용하여 나노입자의 캡핑 에이전트 결합상태와 시차주사현미경과 입도분석기를 이용한 나노입자의 크기 및 뭉침 변화를 확인하였다. $BaTiO_3$ is typical ferromagnetic materials with dielectric constant of above 200. $BaTiO_3$ nanoparticles applications are available for multiple purposes such as nanocapacitors, ferroelectric random access memories, and so on. Applications are is diverse from the dispersion of nanoparticles depending on the route of synthesis. In this study, $BaTiO_3$ nanoparticles were synthesized by two different methods such as oxalate method and sol-gel process (ambient condition sol method). Particle size and dispersion condition were studied according to the preparation method and capping agent. Poly vinyl pyrrolidone (PVP) was used as a capping agent in oxalate method and tetrabutylammonium hydroxide (TBAH) used as a capping agent in sol-gel process each. Cubic crystal structure of $BaTiO_3$ phase could be confirmed by X-ray diffraction analysis. Fourier transform-infrared spectroscopy was employed for the confirmation of the capping agent and $BaTiO_3$ nanoparticles. The particle size and distribution analysis was also performed by particles size analyzer and scanning electron microscope.
Barium titanate (BaTiO 3 : BTO) nanoparticles (NPs) were synthesized by chlorine-free ambient condition sol (ACS) process using heat reflux at low temperature of 90°C. The size distribution and morphology of BTO NPs were investigated by varying the concentration of tetrabutylammonium hydroxide (TBAH). The crystalline size of BTO NPs was decreased with increasing the amount of TBAH capping agent (average size changes from 54.3 to 38.7 nm for 0 to 0.5 M TBAH in X-ray diffraction measurement). The particle size of BTO NPs was principally controlled by a synthetic control of butyl chain of TBAH and also a steric effect of excess amount of TBAH. The dielectric constant of BTO NPs was decreased from 152 to 144 at 1 MHz after an adoption of TBAH capping agent with almost uniform dielectric loss (<0.027). But the dielectric constant of BTO NPs synthesized with various molar ratio of TBAH (0.1, 0.3, and 0.5) did not show a distinguished decrease. At the particle size range in this experiment, the dielectric behavior of BTO NPs was found to be mainly dependent on the TBAH ligands at BTO NPs formed during capping process, not on the size of BTO NPs.
'%3e%3cg id='b'%3e%3cpath id='a' stroke='%23000' stroke-width='2' d='M-6-25H6m-12 3H6m-12 3H6'/%3e%3cuse xlink:href='%23a' y='44'/%3e%3c/g%3e%3cpath stroke='%23fff' d='M0 17v10'/%3e%3ccircle r='12' fill='%23cd2e3a'/%3e%3cpath fill='%230047a0' d='M0-12A6 6 0 0 0 0 0a6 6 0 0 1 0 12 12 12 0 0 1 0-24z'/%3e%3c/g%3e%3cg transform='rotate(-123.69)'%3e%3cuse xlink:href='%23b'/%3e%3cpath stroke='%23fff' d='M0-23.5v3M0 17v3.5m0 3v3'/%3e%3c/g%3e%3c/svg%3e)