A5101854135- Perovskite Materials and Applications
- Chalcogenide Semiconductor Thin Films
- Conducting polymers and applications
- Quantum Dots Synthesis And Properties
- Semiconductor materials and devices
- Organ Transplantation Techniques and Outcomes
- Advanced Photocatalysis Techniques
- Electronic and Structural Properties of Oxides
- Renal Transplantation Outcomes and Treatments
- Advanced Fiber Laser Technologies
- Organ Donation and Transplantation
- Advanced Photonic Communication Systems
- Dialysis and Renal Disease Management
- Hepatocellular Carcinoma Treatment and Prognosis
- Solid-state spectroscopy and crystallography
- Plasma Diagnostics and Applications
- Advancements in Semiconductor Devices and Circuit Design
- Inorganic Chemistry and Materials
- Advanced Semiconductor Detectors and Materials
- Nanomaterials and Printing Technologies
- Electrocatalysts for Energy Conversion
- Organic Electronics and Photovoltaics
- Engineering Applied Research
- Liver Disease Diagnosis and Treatment
- Crystal Structures and Properties
Korea Advanced Institute of Science and Technology
2016-2024
Northwestern University
2023-2024
Sungkyunkwan University
2004-2023
Daejeon University
2018
Kootenay Association for Science & Technology
2016
Samsung (South Korea)
2015
Samsung Medical Center
2004-2014
ON Semiconductor (United States)
2006
Engineering perovskites with anions The bandgap of the perovskite top layer in tandem silicon solar cells must be tuned to ∼1.7 electron volts. Usually, cation composition is varied because bromine-rich anion compositions wide bandgaps are structurally unstable. Kim et al. show that by using phenethylammonium as a two-dimensional additive, along iodine and thiocyanate, films can stabilized. A cell delivered >26% certified power conversion efficiency, device maintained 80% its initial...
Using in situ electrical biasing transmission electron microscopy, structural and chemical modification to n-i-p-type MAPbI3 solar cells are examined with a TiO2 electron-transporting layer caused by bias the absence of other stimuli known affect physical integrity such as moisture, oxygen, light, thermal stress. Electron energy loss spectroscopy (EELS) measurements reveal that oxygen ions released from migrate into under forward bias. The injection is accompanied significant transformation;...
A novel method, named “selective reactivity-assisted sacrificial additive coating”, allowed the BF 4 − from to react selectively with Cs + perovskite, forming CsBF passivate A-site vacancy on surface.
Most memory-chip manufacturers keep trying to supply cost-effective storage devices with high-performance characteristics such as smaller tPROG, lower power consumption and longer endurance. For many years, every effort has been made shrink die size cost improve performance. However, the previously used node-shrinking methodology is facing challenges due increased cell-to-cell interference patterning difficulties caused by decreasing dimension. To overcome these limitations, 3D-stacking...
The solution process is the most widely used method to prepare perovskite absorbers for high performance solar cells due its ease fabrication and low capital cost. However, an insufficient level of reproducibility often a concern. Complex precursor chemistry likely one main reasons issue. Here we report effects triple cation lead mixed-halide aging on quality resulting films device performance. Our study revealed that has great influence colloidal size distribution solution, which then...
Mixed–halide perovskites have emerged as a promising candidate for optoelectronics, due to their tunable optical properties. However, photoinduced phase segregation remains an obstacle stable performance in solar cells. Here, we conducted both bulk and nanoscale measurements elucidate the mechanism of halide ion migration that leads segregation. By utilizing Kelvin probe force microscopy (KPFM) under illumination, observed time-evolution from grain boundaries agreed with photoluminescence...
Light-induced phase segregation poses challenges for the application of mixed-halide hybrid perovskites in photovoltaics, causing voltage deficits. Here, we investigate role chemical composition improving photostability wide bandgap perovskites. We partially substituted formamidinium cation (Cs0.17FA0.83)Pb(Br0.2I0.8)3 with seven alternative cations to achieve a slight blue shift bandgap, typically achieved by increasing bromide content. Among cations, dimethylammonium (DMA) and...
By introducing ZnS between Cu(In, Ga)(S,Se)2 (CIGS) and the CdS, we greatly improved photoelectrochemical (PEC) performance of CIGS photocathode for hydrogen evolution. Chemical structural analysis reveals that enhanced is due to additional band bending driven by in-diffusion Zn into suppression nonradiative recombination. The onset potential was exploited building a tandem device with perovskite absorber bias-free water splitting. A PEC solar-to-hydrogen conversion efficiency exceeding 9%...
One of the primary methods for band gap tuning in metal halide perovskites has been (I/Br) mixing. Despite widespread usage this type chemical substitution perovskite photovoltaics, there is still little understanding structural impacts alloying, with assumption being formation ideal solid solutions. The FASnI3-xBrx (x = 0-3) family compounds provides first example where breaks down, as composition space broken into two unique regimes 0-2.9; x 2.9-3) based on their average structure former...
A novel poly(vinyl)silazane-block-polystyrene diblock copolymer is successfully synthesized by living free-radical polymerization via a reversible addition fragmentation chain transfer (RAFT) route (see figure). The obtained copolymer, having an inorganic volume fraction of 0.69, leads to phase-separation at the nanoscale form ordered nanostructure, which converted well-ordered mesoporous SiCN ceramic after heating 800 °C and maintained up 1400 °C.
Titanium oxide (TiO2) exhibits intrinsically strong absorption of ultraviolet (UV) light, which has been utilized in a variety applications, such as environmental purification/sterilization, health care, and energies. Accordingly, it is greatly demanded to precisely tune further improve the UV TiO2 significantly broaden its versatility. Herein, we report an extraordinary enhancement nanoparticles (NPs) incorporated with graphene nanodots (GNDs) low oxygen concentration. Chemically bonded...
Perovskite nanocrystals (NCs) have attracted increasing interest in the realization of single-photon emitters owing to their ease chemical synthesis, wide spectral tunability, fast recombination rate constant, scalability, and high quantum yield. However, integration a single perovskite NC into photonic structure has yet be accomplished. In this work, highly stable individual zwitterionic ligand-based CsPbBr3 with circular Bragg grating (CBG) is successfully demonstrated. The far-field...
We studied the effects of postsynthesis thermal treatments on material properties CH3NH3PbI3 perovskite films and their photovoltaic performance. Kelvin probe force microscopy revealed existence a positive potential barrier at grain boundaries, which is known to be beneficial by suppressing carrier recombination. The height increased with annealing duration, directly correlated device origin appeared chemical inhomogeneity as Nano-Auger electron spectroscopy. Qualitatively similar...
Sb 2 Se 3 possesses a quasi‐1D (Q1D) structure, which creates an anisotropic charge transporting behavior in the carrier transport is very efficient along Q1D direction, beneficial for solar cells as long absorber properly aligned preferred orientation. However, prone to form donor‐like defects, such V , that are detrimental performance. Therefore, both growth of orientations and suppression formation crucial achieving with high efficiency. Herein, importance fine control extra supply during...
Domino kidney paired donation (KPD) is a method by which an altruistic living nondirected donor (LND) allocated to pool of incompatible donor-recipient pairs (DRP) and series KPDs initiated. To evaluate the feasibility clinical outcomes multicenter domino KPD, we retrospectively analyzed cohort DRPs who underwent KPD between February 2001 July 2007 at one 16 transplant centers. One hundred seventy-nine transplants were performed, with 70 chains initiated LND. There 45 two-pair chains, 15...
Background. Patients with end-stage renal disease (ESRD) have a greatly increased risk of premature cardiovascular disease. Peritoneal dialysis (PD) patients more atherogenic lipid profiles than haemodialysis patients. In this retrospective cohort study, we evaluated whether statin use is associated improved mortality in incident PD
A passivation strategy for the perovskite/HTL interface is presented based on potassium acetate (K‐Ac). Since K‐Ac soluble in both polar and nonpolar solvent, deposition of top bottom perovskite possible. With this advantage, universality interfacial at HTL/perovskite applied to various configurations with ranges bandgap reported. Regarding p–i–n configuration, materials characterizations reveal that a layer underneath modifies orientations, resulting better charge transport film properties....
Ir is one of the most efficient oxygen evolution reaction (OER) catalysts; however, it also rarest and expensive elements. Therefore, highly desirable to develop catalysts with nanostructures that reduce consumption by maximizing surface-to-volume ratio without limiting mass transport reactants products reactions. OER on a template consisted porous nanotubes (PNTs) based Ni are fabricated. The Ir/Ni PNTs offer multiple benefits, including high catalytic performance (potential 1.500 V vs....
Nitride materials with mixed ionic and covalent bonding character resulting good charge transport properties are attractive for optoelectronic devices.
Abstract Minimizing optical losses of the incident light at window layers is one effective strategies for high photoresponse to achieve highly efficient perovskite/silicon tandem cells. The enhancement monolithic cells via rationally controlling their consisting C 60 and indium tin oxide (ITO) reported. simulation experimental results are consistent that employing thinner ITO would reduce caused by absorption/reflection incident, which should lead increased photocurrent density. However, it...
We investigated the role of hollow perovskite architectures in enhancing photostability mixed halide wide-bandgap perovskites. focused on mitigating photoluminescence (PL) peak shifts caused by phase segregation when exposed to light. By analyzing optical and structural properties bromide/iodide thin films, we observed that incorporation structures reduced ionic conductivity leading improved compared non-hollow samples. The films exhibited increased bandgap. High-power laser irradiation was...