Jongha Lee  Byeongjun Yoo  Hakyong Lee  Gi Doo Cha  Hee‐Su Lee  Youngho Cho  Sang Yeon Kim  Hyunseon Seo  Woongchan Lee  Donghee Son  Myungjoo Kang  Hyung Min Kim  Yong Il Park  Taeghwan Hyeon  Dae‐Hyeong Kim 《Advanced materials (Deerfield Beach, Fla.)》2017,29(1)

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Hyun‐Gu Kim  Kwon‐Hyeon Kim  Jang‐Joo Kim 《Advanced materials (Deerfield Beach, Fla.)》2017,29(39)

Highly efficient, yellow‐fluorescent organic light‐emitting diodes with a maximum external quantum efficiency exceeding 25.0% and extended lifetime are reported using iridium‐complex sensitizers doped in an exciplex host. Energy transfer processes reduce the lifetime of the exciplex and excitons on the Ir complexes and enable an excited state to exist in a conventional fluorescent emitter, thereby increasing device lifetime. The device stability depends on the location of the excited state.  相似文献   

    

Juwon Lee  Sangyeon Pak  Paul Giraud  Young‐Woo Lee  Yuljae Cho  John Hong  A‐Rang Jang  Hee‐Suk Chung  Woong‐Ki Hong  Hu Young Jeong  Hyeon Suk Shin  Luigi G. Occhipinti  Stephen M. Morris  SeungNam Cha  Jung Inn Sohn  Jong Min Kim 《Advanced materials (Deerfield Beach, Fla.)》2017,29(33)

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Pil Ju Youn;Mun Young Woo;Jong Hyeon Won;Jeong Min Im;Jun Hyuk Lee;Jun Hong Noh;Jeong Hwan Han; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(52):2407036

In fabricating high-efficiency all-perovskite tandem solar cells (APTSCs) with a p-i-n configuration, the electron transport layer (ETL) plays a critical role in facilitating the transport of photogenerated electrons from the front cell to the recombination layer and protecting the front cell from damage during rear cell fabrication. This study introduces aluminum-doped In2O3 (AIO) films grown by atomic layer deposition (ALD) as a promising ETL for high-efficiency APTSCs. ALD-grown AIO films with an optimized Al concentration exhibit superior charge transport characteristics, excellent transparency, and damage-resistant barrier properties against solution infiltration compared with conventional SnO2 ETLs and undoped ALD In2O3. Using an ALD SnO2/3 at.% AIO bilayer as the electron transport layer, an efficiency of 18.33% is achieved from single-junction wide bandgap perovskite solar cells. Furthermore, the use of ALD SnO2/3 at.% AIO ETL enables the reliable fabrication of APTSCs with negligible solution damage to the front cell and minimized power loss. Consequently, APTSC employing the ALD AIO-based ETL exhibit an excellent photoconversion efficiency of 25.46%, outperforming APTSCs with the ALD SnO2 ETL.  相似文献   

    

Jingwen Wu;Zhibo Ren;Xindi Xu;Dong Hyeon Mok;Weiqi Guo;Ke Ye;Peng Shen;Weiyi Zhang;Baoxin Ni;Shusheng Wan;Gwonho Yu;Wen-Bin Cai;Seoin Back;Jinyi Wang;Kun Jiang; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(52):2407374

Green hydrogen production from water splitting is a feasible way for intermittent renewable energy storage and utilization, where the exploration and scale-up preparation of high-performance anodic oxygen evolution electrocatalysts are critical prerequisites for its industrial-level applications. Herein, a chemical bath deposition of FeNi3 intermetallic alloys onto Ni mesh support is performed, which delivers a current density of 0.62 A cm−2 at 1.72 V versus reversible hydrogen electrode for alkaline water oxidation in 1 m KOH and an excellent electrolysis stability at 0.2 A cm−2 for over 300 h. Moreover, via 3D computational fluid dynamics simulation and flow field optimization, a homogeneous deposition of ≈5400 cm2 NiFe anode is demonstrated within 4 min using the developed flow bath reactor. Once integrating the as-prepared NiFe anodes into alkaline electrolyzer stack, the voltage variation between each unit cell is below 40 mV at a total operation current of 71 A, or ca. current density of 0.2 A cm−2, confirming the uniformity of this batch synthesis protocol and its great potential for industrial alkaline water electrolysis.  相似文献   

    

So‐Hyeon Lee  Jin‐A Ko  Hae‐Soo Kim  Min‐Ho Jo  Joong‐Su Kim  Doman Kim  Jeong‐Yong Cho  Young‐Jung Wee  Young‐Min Kim 《Journal of food science》2019,84(11):3186-3193

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Gyu‐Hyeon Park  Kornelius Nielsch  Andy Thomas 《Advanced Materials Interfaces》2019,6(3)

Ultrathin 2D transition metal dichalcogenide (TMD) thin films have attracted much attention due to their very good electrical, optical, and electrochemical properties. Chemical vapor deposition (CVD) and atomic layer deposition (ALD), which is in some regards an enhanced version of CVD, are techniques that can provide exceptionally conformal large‐area coatings, even for complex surface geometries. Besides, these techniques include the transport of one or more precursor chemicals in the gas phase onto a substrate. Subsequently, a chemical reaction occurs, resulting in the deposition of a film of a solid material on the substrate. One of the advantageous aspects of chemical deposition methods, such as CVD and ALD, is the growth of thin films onto a variety of substrates as well as 3D structures. Because of their chemical approach, these techniques are well suited to synthesizing 2D materials (2DMs) with a low defect concentration. Furthermore, the scalability would allow industrial application, as opposed to, e.g., micromechanical cleavage. Here, the recent progress in 2D TMD thin films is reviewed and the current applications of these materials fabricated by CVD and ALD are surveyed.  相似文献   

    

Jiuk Jang  Byungkook Oh  Subin Jo  Sunghee Park  Hyeon Seok An  Seunghee Lee  Woon Hyung Cheong  Seunghyup Yoo  Jang‐Ung Park 《Advanced Materials Technologies》2019,4(7)

Human‐interactive displays involve the interfacing of a stimuli‐responsive sensor with a human‐readable response. Human‐readable responses include the five recognized senses, i.e., sight (vision), hearing (audition), taste (gustation), smell (olfaction), and touch (somatosensation). Vision is considered to be the most informative human stimulus so that the visualization of electrical, thermal, and mechanical data is important for various applications. Herein, the fabrication of human‐interactive displays is demonstrated in which active‐matrix arrays of pressure‐sensitive Si transistors with air dielectric layers are fully integrated with pixels of organic light‐emitting diodes (OLEDs). In this way, the luminance of the individual OLED pixels can be increased locally by pressing the display, and the luminance is dependent on the magnitude of the applied pressure. Furthermore, the air dielectric layer of transistors provides outstanding electrical properties, including high transconductance and negligible hysteresis. 3D integration of these transistors with dual‐side emissive OLED pixels is also demonstrated. Local pressing increases the light intensity of OLED pixel and then the underlaid Si channel can absorb this light successively to generate additional photocurrents from the pressure‐sensitive transistor, further enhancing its sensitivity. This human‐interactive display can visualize tactile pressure directly, suggesting the substantial promise as next generation displays for intelligent human‐machine interfacing.  相似文献   

    

Seungjin Lee  Da Bin Kim  Jae Choul Yu  Chung Hyeon Jang  Jong Hyun Park  Bo Ram Lee  Myoung Hoon Song 《Advanced materials (Deerfield Beach, Fla.)》2019,31(20)

Metal halide perovskites (MHPs) have emerged as promising emitters because of their excellent optoelectronic properties, including high photoluminescence quantum yields (PLQYs), wide‐range color tunability, and high color purity. However, a fundamental limitation of MHPs is their low exciton binding energy, which results in a low radiative recombination rate and the dependence of PLQY on the excitation intensity. Under the operating conditions of light‐emitting diodes (LEDs), the injected current densities are typically lower than the trap density, leading to a low actual PLQY. Moreover, the defects not only initiate the decomposition of MHPs caused by extrinsic factors, but also intrinsically stimulate ion migration across the interface and lead to the corrosion of electrodes due to interaction between those electrodes, even under inert conditions. The passivation of defects has proven to be effective for mitigating the effects of defects in MHPs. Herein, the origins and theoretical calculations of the defect tolerance in MHPs and the impact of defects on both the performance and stability of perovskite LEDs are reviewed. The passivation methods and materials for MHP bulk films and nanocrystals are discussed in detail. Based on the currently reported advances, specific requirements and future research directions for display applications are suggested.  相似文献   

    

Hyeon Woo Park  Jangho Roh  Yong Bin Lee  Cheol Seong Hwang 《Advanced materials (Deerfield Beach, Fla.)》2019,31(32)

The negative capacitance (NC) effect in ferroelectric thin films has attracted a great deal of attention from the material and semiconductor device communities because it could be a possible solution to the impending problems related to field‐effect transistor power consumption and dynamic random‐access memory charge loss. A short discussion on the fundamental premise of the NC effect is presented. A phase‐field model based on the time‐dependent Ginzburg–Landau (TDGL) formalism in conjunction with the Chensky–Tarasenko (C–T) formalism for multidomain configuration is then developed to reveal the subtle correlation between the domain wall motion and NC effect for different thicknesses of ferroelectric and dielectric films. When a ferroelectric film becomes thin enough, a stripe domain structure can be achieved through competition between the electrostatic energy and domain wall energy. This stripe domain structure is quite resilient to transition to a homogeneous polarization state, making it very useful for (quasi‐)static NC operation. Finally, the physical implications of the numerical results are explored with analytical modeling. It is identified that the domain wall motion in the stripe domain structure remains dominated by the external field, even when the entire film is in the (quasi‐)static NC state.  相似文献