HOME OF MOLECULAR SEMICONDUCTORS


From nano to micro scales

A Gateway toward fertile and stable life of next generation

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 Our group is affiliated with department of Chemistry and Division of Advanced Materials Science, graduate program in POSTECH.

 Our group research focuses on the development of new functional materials through the growth and property studies of functional molecular crystals and molecular network systems as they provide enormous opportunities for the success considering the unlimited number of target molecules, and the intrinsic property of molecular crystal that frequently exhibit new properties upon crystallization, different from those of the original molecules. More specifically, we are interested in growing crystals of molecules that are electrically, optically active to eventually apply them in various applications, such as energy conversion systems, next generation semiconductors, superconductors, etc. We are also interested in their property changes depending on their morphologies, and upon dimension scales spanning from nano to micron sizes. We also challenge important hurdles present in conventional nanoscale materials including carbon nanotubes, graphene, and 2D metal dichalcogenides, etc. Molecular network systems embrace molecule-backboned materials including metal organic frameworks (MOFs) and covalent organic frameworks (COFs), of which properties could be varied upon the selection of molecular component. Our contribution in this subject is to develop synthetic methods for their formation into various dimensions, especially, in one- or two-dimensions. Our ultimate goal for the research on molecular network systems is to rebuild traditional inorganic solid state network systems into pure molecular network systems.

 In this regard, we have been working on following specific subjects:

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2D COF

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C70  Cube

1. Development of various crystal growth methods in all possible phases, from traditional solution phase to vapor phase reactions.

2. Fabrication of molecular crystal electrical devices to examine their electrical/optical properties.

3. Crystallographic and spectroscopic analyses to understand the property changes upon crystallization & the structure-property correlation using the Synchrotron facility on campus (Pohang Accelerator laboratory, PAL) as well as lab-equipped spectrometers.

4. Development of efficient alkali metal doping methods for the studies of higher conducting molecular crystal systems as well as superconducting molecular systems.

5. Development of synthetic methods for 1D, 2D MOFs, COFs.

6. Reconstruction of inorganic network systems using soft molecules. 

7. Understanding the growth mechanism of 2D materials on solid catalyst substrates.

News

Recent Publications

  • Youngkwan's paper entitled "Ultrasmooth organic films via efficient aggregation suppression by a low-vacuum physical vapor deposition" has been accepted in Materials. Congratulations! 2021.11. 24

  • Dr. Jinyoung Koo's paper entitled "Bismuth organic frameworks exhibiting enhanced phosphorescence" has been accepted in Commun. Chem. Congratulations! 2021.11. 10

  • Dr. Jinyoung Koo's paper entitled "The anisotropic electrical conductivity of a single-crystalline oxo-bridged Cr4(III)Mo2(VI) heterometallic complex" has been accepted in Inorg.Chem. Congratulations! 2021.07.29

  • Kwangjin's paper entitled "Viscosity effect on strategic kinetic overgrowth of molecular crystals in various morphologies: concave and octapod fullerene crystals." has been accepted in RSC Adv. Congratulations! 2021.06.04

  • Hyeyeon was awarded "The next generation of academics-research grants for PH.D. students" in National Research Foundation of Korea (NRF)  Congratulations! 2021.06.03

  • Dr. Jinyoung Koo's paper entitled "Phase Change-Driven Radical Population and Electrical Conductivity Increases of Organic Radical Crystals by Mild Heating" has been accepted in J. Phys. Chem. C. Congratulations! 2021.05.06

  • Jiwon's paper entitled "Solvent-effected coordination variation of flexible ligands to Cu(II) for the formation of 1D and 2D secondary building units for metal-organic frameworks" has been accepted in Inorg.Chem.        Congratulations! 2021.03.17

  • Dr. Jinyoung Koo proposal was accepted by Basic Science Research program (Sejong Science Fellowship) managed by the National Research Foundation of Korea (NRF). Congratulations! 2021.03.08

  • Dr. Sungwook Woo has joined as Research Assistant Professor of NMRL group. Welcome! 2021.03.02 

  • Yelim and Yunju has joined as new members of NMRL group. Welcome!   2021.02.22 

  • Yohwan's paper entitled "Emulsions by Miscible Solvents: Origin for Anti-solvent Crystallization" has been accepted in CrystEngComm.  Congratulations! 2020.12.12 

  • Yoolim's paper entitled "Morphology-retained Conversion of Neutral to Mixed Valence Tetrathiafulvalene Crystals through a Spontaneous Redox Reaction" has been accepted in ACS Appl. Electron. Mater. Congratulations! 2020.12.03 

  • Hyesoo's paper entitled "Highly Pure Pentacene Crystals Grown by Physical Vapor Transport: The Critical Role of Carrier Gas" has been accepted in J. Mater. Chem. C. Congratulations! 2020.11.30 

  • Hyeyeon's paper entitled "Specific stacking angles of bilayer graphene grown on atomic-flat and -stepped Cu surfaces." has been accepted in npj 2D Mater. Appl. Congratulations! 2020.09.16 

  • Taeyeon (Dr. Kwon) has successfully defended her Ph. D. thesis.  Congratulations! 2020.06.17

  • Yohwan (Dr. Park) has successfully defended his Ph. D. thesis.  Congratulations! 2020.06.17

  • Taekyung (Dr. Yoon) has successfully defended his Ph. D. thesis.  Congratulations! 2020.06.17

  • Taeyeon's paper entitled "Highly Conducting and Flexible Radical Crystals." has been accepted in Angew. Chem. Int. Ed. Congratulations! 2020.06.15

  • Youngkwan's paper entitled "Surface-guided polymorphism control of titanyl phthalocyanine single crystals." has been accepted in  Inorg. Chem. Front. Congratulations! 2020.04.15

  • Taekyung's paper entitled "Discovery of sodium-doped triphenylene superconductor through searching the organic material database" has been accpeted in Chem. Mater. Congratulations! 2020.03.25

  • Myeonggeun's paper entitled "Smooth and Large scale Organometallic Complex Film by Vapor-Phase Ligand Exchange Reaction." has been accepted in RSC Adv. Congratulations! 2020.03.05

  • Yoon, Y.; Lee, J; Lee, S; Kim, S; Choi, H. C. Materials, 2021, 14, 7247. Ultrasmooth organic films via efficient aggregation suppression by a physical vapor deposition

  • Koo, J. Y.; Lee, C.; Joo, T.; Choi, H. C. Commun. Chem. 2021, accepted. Bismuth organic frameworks exhibiting enhanced phosphorescence.  

  • Koo, J. Y.; Oh, J.; Hyun, G.; Choi, H. C.; Song, I; Yoon, S. M.;  Inorg.Chem. 2021, 60, 13262-13268.  The anisotropic electrical conductivity of a single-crystalline oxo-bridged Cr4(III)Mo2(VI) heterometallic complex.

  • Song, K.; Koo, J. Y.; Choi, H. C. RSC Advances, 202111, 20992 - 20996.   Viscosity effect on strategic kinetic overgrowth of molecular crystals in various morphologies: concave and octapod fullerene crystals.

  • Koo, J. Y.#; Kwon, T.#; Ahn, Y.; Choi, H. C. J. Phys. Chem. C. 2021. 125, 10991-10997.  Phase Change-Driven Radical Population and Electrical Conductivity Increases of Organic Radical Crystals by Mild Heating. (# these authors contributed equally to this work)

  • Park, J.; Koo, J. Y.; Choi, H. C. Inorg.Chem. 202160, 5376–5382. Solvent-effected coordination variation of flexible ligands to Cu(II) for the formation of 1D and 2D secondary building units for metal-organic frameworks.  

  • Kim, H. S.; Kim, S.; Koo, J. Y.; Choi, H. C. J. Mater. Chem. C. 2021, 9, 1911-1917. Highly Pure Pentacene Crystals Grown by Physical Vapor Transport: The Critical Role of Carrier Gas. <Back cover>

  • Lee, H.; Kim, J.; Lee, J.; Park, H.; Park, Y.; Jung, S.; Lim, J.; Choi, H. C.; Kim, W. J. Biomaterials. 2020, 263, 120402. In vivo Self-Degradable Graphene Nanomedicine Operated by DNAzyme and Photo-Switch for Controlled Anticancer Therapy.

  • Cho, H.#; Park, Y#.; Kim, S.; Ahn, T.; Kim, T.; Choi, H. C. npj 2D Mater. Appl. 2020. 4, 35. Specific stacking angles of bilayer graphene grown on atomic-flat and -stepped Cu surfaces. (# these authors contributed equally to this work)

  • Yoon, T.#; Park, I.#; Nguyen, T. P.; Kim, D. Y.; Lee, J.; Shim, J. H.; Choi, H. C. Chem. Mater. 2020, 32. 3358-3364. Discovery of Sodium-Doped Triphenylene Superconductors by Searching the Organic Material Database. (# these authors contributed equally to this work)

  • Yoon, Y.; Kim, S.; Choi, H. C. NPG Asia Mater. 2020, 12, 16. Selective growth of α-form zinc phthalocyanine nanowire crystals through flow rate control of physical vapor transport method.

  • Yoon, T.; Koo, J. Y.; Choi, H. C. Nano Lett. 2020, 20, 612-617. High Yield Organic Superconductors via Solution-Phase Alkali Metal Doping at Room Temperature.​​