Jae Cheon Kim

Learn More
Nitrogen fixation is essential for the synthesis of many important chemicals (e.g., fertilizers, explosives) and basic building blocks for all forms of life (e.g., nucleotides for DNA and RNA, amino acids for proteins). However, direct nitrogen fixation is challenging as nitrogen (N₂) does not easily react with other chemicals. By dry ball-milling graphite(More)
The charge sharing effect in pixelated CdZnTe (CZT) detectors with a common anode steering grid has been studied. The impact on energy resolution of weighting potential cross-talk and ballistic deficit due to cathode signal shaping has been investigated. A detailed system modeling package considering charge induction, electronic noise, pulse shaping, and(More)
Keywords: Semiconductor detector CdZnTe Electron drift velocity Drift time variation Three-dimensional (3D) position-sensitive Cathode waveform Multiple-pixel events Compton imaging a b s t r a c t In pixelated CdZnTe detectors, multiple interaction gamma-ray events are critical because they permit Compton imaging. However, in large-volume CdZnTe crystals,(More)
Challenging precious Pt-based electrocatalysts for dye-sensitized solar cells (DSSCs), graphene nanoplatelets that are N-doped at the edges (NGnPs) are prepared via simply ball-milling graphite in the presence of nitrogen gas. DSSCs based on specific nanoplatelets designated "NGnP5" display superior photovoltaic performance (power conversion efficiency,(More)
Highly efficient counter electrodes (CEs) for dye-sensitized solar cells (DSSCs) were developed using thin films of scalable and high-quality, nitrogen-doped graphene nanoplatelets (NGnP), which was synthesized by a simple two-step reaction sequence. The resultant NGnP was deposited on fluorine-doped SnO2 (FTO)/glass substrates by using electrospray(More)
In a pixelated detector, an electron cloud can be collected by and shared between several adjacent pixels. By including these charge-sharing events, the Compton-imaging efficiency can be improved for 3D position sensitive room-temperature CdZnTe gamma-ray detectors. Simulated photopeak events that trigger three separate pixels with two pixels being adjacent(More)
  • 1