Dong-Kyun Ko Research Group: NMD Lab at NJIT

Journal Publications

● M. M. Al Mahfuz; R. Islam; Y. Zhang; J. Baek; J. Park; S. Lee; D. -K. Ko, "Mid-wavelength infrared photoconductive film synthesized from PbSe molecular ink," Appl. Phys. Lett., 123, 203301 (2023)

● C. Yoo; V. Adepu; S. S. Han; J. H. Kim; J.-C. Shin; J. Cao; J. Park; M. M. Al Mahfuz; L. Tetard; G. -H. Lee; D. -K. Ko; P. Sahatiya; Y. Jung, "Low Temperature Centimeter-Scale Growth of Layered 2D SnS for Strain-Invariant Piezoelectric Kirigami Devices," ACS Nano, 17, 20680-20688 (2023)

● M. M. Al Mahfuz; J. Park, R. Islam, D. -K. Ko, "Colloidal Ag2Se Intraband Quantum Dots," Chem. Commun., 59, 10722 (2023)

● M. M. Al Mahfuz; J. Park, R. Huebner, S. Lee, D. -K. Ko, "Schottky Photodiodes Based on Mid-Wavelength Infrared Intraband Colloidal Quantum Dots - Surface Ligand and Metal Contact Studies," J. Mater. Chem. C, 11, 7714-7721 (2023)

● J. Park; M. M. Al Mahfuz; R. Huebner; D. -K. Ko, "Uncooled Mid-Wavelength Infrared Photoconductive Detectors Based on PbSe Nanocrystals," ACS Appl. Electron. Mater., 5, 2386-2392 (2023)

● J. Park; M. M. Al Mahfuz; R. Huebner; D. -K. Ko, "Mid-Infrared Photoconductive Detectors Fabricated From Solution-Processed PbSe Nanocrystals," ECSarXiv, DOI: 10.1149/osf.io/pmv3x (2022)

● D.-K. Ko, "Intraband Colloidal Quantum Dots for Low-Cost Mid-Wavelength Infrared Detectors," IEEE Research and Applications of Photonics in Defense (RAPID), DOI: 10.1109/RAPID54472.2022.9911546 (2022)

● S. S. Han; T. -J. Ko; M. S. Shawkat; A. K. Shum; T. -S. Bae; H. -S. Chung; J. Ma; S. Sattar; S. B. Hafiz; M. M. Al Mahfuz; S. A. Mofid; J. A. Larsson; K. H. Oh; D. -K. Ko; and Y. Jung, "Peel-and-Stick Integration of Atomically Thin Nonlayered PtS Semiconductors for Multidimensionally Stretchable Electronic Devices," ACS Appl. Mater. Interfaces, 14, 20268-20279 (2022)

● D. H. Lee; H. Park; M. Clevenger; H. Kim; C. S. Kim; M. Liu; G. Kim; H. W. Song; K. No; S. Y. Kim; D.-K. Ko; A. Lucietto; H. Park; S. Lee, "High-Performance Oxide-Based p-n Heterojunctions Integrating p-SnOx and n-InGaZnO," ACS Appl. Mater. Interfaces, 13, 55676-55686 (2021)

● S. B. Hafiz; M. M. Al Mahfuz; S. Lee; D.-K. Ko, "Midwavelength Infrared p-n Heterojunction Diodes Based on Intraband Colloidal Quantum Dots," ACS Appl. Mater. Interfaces, 13, 49043-49049 (2021)

● S. B. Hafiz; M. M. Al Mahfuz; D. -K. Ko, "Intraband Quantum Dot Barrier Devices - Optimization of Energy Level
Alignment," ECS Trans., 102, 45-51 (2021).

● M. Liu; X. Wang; H. W. Song; M. Clevenger; D. -K. Ko; K. No; S. Lee, "Origin of an unintended increase in carrier density of ternary cation-based amorphous oxide semiconductors," Appl. Surf. Sci., 556, 149676 (2021).

● M. S. Shawkat; S. B. Hafiz; M. M. Islam; S. A. Mofid; M. M. Al Mahfuz; A. Biswas; H. -S. Chung; E. Okogbue; T. -J. Ko; D. Chanda; T. Roy; D. -K. Ko; Y. Jung, "Scalable Van der Waals Two-Dimensional PtTe2 Layers Integrated onto Silicon for Efficient Near-to-Mid Infrared Photodetection," ACS Appl. Mater. Interfaces, 13, 15542-15550 (2021).

● S. B. Hafiz; M. M. Al Mahfuz; D. -K. Ko, "Vertically-Stacked Intraband Quantum Dot Devices For Mid-Wavelength Infrared Photodetection," ACS Appl. Mater. Interfaces, 13, 937-943 (2021).

● A. Reed; C. Stone; K. Roh; H. W. Song; X. Wang; M. Liu; D. -K. Ko; K. No; S. Lee, "The Role of Third Cation Doping on Phase Stability, Carrier Transport and Carrier Suppression in Amorphous Oxide Semiconductors," J. Mater. Chem. C, 8, 13798-13810 (2020).

● L. Tsybeskov; M. Alam; S. B. Hafiz; D. -K. Ko; A. Bratkovsky; X. Wu; D. J. Lockwood, "Photoluminescence in PbS Nanocrystal Thin Films: Nanocrystal Density, Film Morphology and Energy Transfer," J. Appl. Phys., 128, 134301 (2020).

● T. -J. Ko; S. S. Han; E. Okogbue; M. Shawkat; M. Wang; J. Ma; T. S. Bae; S. B. Hafiz; D. -K. Ko; H. -S. Chung; K. H. Oh; Y. Jung, "Wafer-Scale 2D PtTe2 Layers-Enabled Kirigami Heaters with Superior Mechanical Stretchability and Electro-Thermal Responsiveness," Appl. Mater. Today, 20, 100718 (2020).

● S. B. Hafiz; M. M. Al Mahfuz; M. R. Scimeca; S. Lee; S. J. Oh; A. Sahu; D. -K. Ko, "Ligand engineering of mid-infrared Ag2Se colloidal quantum dots," Physica E: Low Dimens. Syst. Nanostruct., 123, 114223 (2020).

● S. B. Hafiz; M. M. Al Mahfuz; D. -K. Ko, "Mid-Wavelength Infrared Responsivity of Colloidal Quantum Dot/Organic Hybrid Photodetectors," ECS Trans., 97, 109-115 (2020).

● M. A. Hossain; S. Jeon; J. Ahn; J. Bang; H. K. Woo; S. B. Hafiz; D. -K. Ko; S. J. Oh, "Property Engineering Through Nanomaterial Chemical Transformation of Colloidal Nanocrystal Thin Films," Appl. Surf. Sci., 513, 145721 (2020).

● N. Chen; M. R. Scimeca; S. J. Paul; S .B. Hafiz; D. -K. Ko; A. Sahu, "High-Performance Thermoelectric Silver Selenide Thin Films Cation Exchanged from a Copper Selenide Template," Nanoscale Adv., 2, 368-376 (2020).

● H. K. Woo; M. S. Kang; T. Park; J. Bang; S. Jeon; W. S. Lee; J. Ahn; G. Cho; D. -K. Ko; Y. Kim; D. -H. Ha; S. J. Oh, "Colloidal-Annealing of ZnO Nanoparticles to Passivate Traps and Improve Charge Extraction in Colloidal Quantum Dot Solar Cells," Nanoscale, 11, 17498-17505 (2019).

● S. B. Hafiz; M. R. Scimeca; A. Sahu, D.-K. Ko, "Mid-Infrared Colloidal Quantum Dot Based Nanoelectronics and Nano-Optoelectronics," ECS Trans., 92, 11-16 (2019).

● S. Hafiz; M. R. Scimeca; P. Zhao; I. J. Paredes; A. Sahu; D. -K. Ko, "Silver Selenide Colloidal Quantum Dots for Mid-Wavelength Infrared Photodetection," ACS Appl. Nano Mater., 2, 1631-1636 (2019).

● S. Hafiz; M. Scimeca; A. Sahu; D. -K. Ko, "Colloidal Quantum Dots for Thermal Infrared Sensing and Imaging," Nano Convergence, 6, 7 (2019).

- Selected as Best Paper Award of 2019 https://sympo.nanokorea.or.kr/2021/mail/210630/newsletter.html

● C. Sun; A. H. Goharpy; A. Rai; T. Zhang; D. -K. Ko, "Paper Thermoelectrics: Merging Nanotechnology with Naturally Abundant Fibrous Material," ACS Appl. Mater. Interfaces, 8, 22182-22189 (2016).

- Highlighted by Nanowerk Spotlight http://www.nanowerk.com/spotlight/spotid=44295.php

● K. -H. Kim; D. -K. Ko; Y. -T. Kim; N. H. Kim; J. Paul; C. B. Murray; R. Acharya; Y. H. Kim; W. F. DeGrado; G. Grigoryan, "Protein-Directed Self-Assembly of a Fullerene Crystal," Nat. Commun., 7, 11429 (2016).

● D. -K. Ko; A. Murano; S. K. Suh; D. Kim; G. W. Hwang; J. C. Grossman; V. Bulovic; M. G. Bawendi, "Photovoltaic Performance of PbS Quantum Dots Treated with Metal Salts," ACS Nano, 10, 3382-3388 (2016).

● D. -K. Ko; P. R. Brown; M. G. Bawendi; V. Bulovic, "p-i-n Heterojunction Solar Cells with a Colloidal Quantum-Dot Absorber Layer," Adv. Mater., 26, 4845-4850 (2014).

● K. M. McPeak; B. Opasanont; T. Shibata; D. -K. Ko; M. A. Becker; S. Chattopadhyay, H. P. Bui; T. P. Beebe; B. A. Bunker; C. B. Murray; J. B. Baxter, "Microreactor Chemical Bath Deposition of Laterally Graded Cd1-xZnxS Thin Films: A Route to High-Throughput Optimization for Photovoltaic Buffer Layers," Chem. Mat., 25, 297-306 (2013).

● J. -H. Choi; A. T. Fafarman; S. J. Oh; D. -K. Ko; D. K. Kim; D. T. Diroll; S. Muramoto; J. G. Gillen; C. B. Murray; C. R. Kagan, "Bandlike Transport in Strongly Coupled and Doped Quantum Dot Solids: A Route to High-Performance Thin-Film Electronics," Nano Lett., 12, 2631-2638 (2012).

● D. -K. Ko; Y. J. Kang; C. B. Murray, "Enhanced Thermopower via Carrier Energy Filtering in Solution-Processable Pt-Sb2Te3 Nanocomposites," Nano Lett., 11, 2841-2844 (2011).

● A. Dong; J. Chen; S. J. Oh; W. -K. Koh; F. Xiu; X. Ye; D. -K. Ko; K. L. Wang; C. R. Kagan; C. B. Murray, "Multiscale Periodic Assembly of Striped Nanocrystal Superlattice Films on a Liquid Surface," Nano Lett., 11, 841-846 (2011).

● Y. -W. Liu; D. -K. Ko; S. J. Oh; T. R. Gordon; V. Doan-Nguyen; T. Paik; Y. Kang; X. Ye; L. Jin; C R. Kagan; C. B. Murray, "Near-Infrared Absorption of Monodisperse Silver Telluride (Ag2Te) Nanocrystals and Photoconductive Response of Their Self-Assembled Superlattices," Chem. Mat., 23, 4657-4659 (2011).

● D. -K. Ko; C. B. Murray, "Probing the Fermi Energy Level and the Density of States Distribution in PbTe Nanocrystal (Quantum Dot) Solids by Temperature-Dependent Thermopower Measurements," ACS Nano, 5, 4810-4817 (2011).

● T. Paik; D. -K. Ko; T. R. Gordon; V. Doan-Nguyen; C. B. Murray, "Studies of Liquid Crystalline Self-Assembly of GdF3 Nanoplates by In-Plane, Out-of-Plane SAXS," ACS Nano, 5, 8322-8330 (2011).

● A. T. Fafarman; W. -K. Koh; B. T. Diroll; D. K. Kim; D. -K. Ko; S. J. Oh; X. Ye; V. Doan-Nguyen; M. R. Crump; D. C. Reifsnyder; C. B. Murray; C. R. Kagan, "Thiocyanate-Capped Nanocrystal Colloids: Vibrational Reporter of Surface Chemistry and Solution-Based Route to Enhanced Coupling in Nanocrystal Solids," J. Am. Chem. Soc., 133, 15753-15761 (2011).

● D. -K. Ko; J. J. Urban; C. B. Murray, "Carrier Distribution and Dynamics of Nanocrystal Solids Doped with Artificial Atoms," Nano Lett., 10, 1842-1847 (2010).

● Y. Jung*; D. -K. Ko*; R. Agarwal, "Synthesis and Structural Characterization of Single-Crystalline Branched Nanowire Heterostructures," Nano Lett., 7, 264-268 (2007). * equally contributed

● S. -H. Lee; D. -K. Ko; Y. Jung; R. Agarwal, "Size-Dependent Phase Transition Memory Switching Behavior and Low Writing Currents in GeTe Nanowires," Appl. Phys. Lett., 89, 223116 (2006).

● Y. Jung; S. -H. Lee; D. -K. Ko; R. Agarwal, "Synthesis and Characterization of Ge2Sb2Te5 Nanowires with Memory Switching Effect," J. Am. Chem. Soc., 128, 14026-14027 (2006).

Conference Abstracts / Talks & Presentations (Selected)

● D. -K. Ko, "Mid-Infrared Optoelectronic Sensors Based on Intraband Colloidal Quantum Dots," Graduate Seminar, Department of Materials Science and Engineering, Korea University, Seoul, South Korea, May 2023

● D. -K. Ko; J. Park; M. M. Al Mahfuz; R. Huebner, 242nd Electrochemical Society (ECS) Meeting, "Mid-Infrared Photoconductive Detectors Fabricated from Solution-Processed PbSe Nanocrystals," oral

● D. -K. Ko, 2022 IEEE Research and Applications of Photonics in Defense Conference (RAPID), "Intraband Colloidal Quantum Dots for Low-Cost Mid-Wavelength Infrared Detectors," oral

● "Materials Science and Device Physics of Intraband Colloidal Quantum Dots for Mid-Infrared Detector Applications," invited tutorial lecture presented at 22nd International Meeting on Information Display (IMID 2022), Busan, South Korea, Aug. 2022

● "Intraband Quantum Dot Technology: Advances in Materials Design and Device Structure for Mid-Infrared Optoelectronics", invited/awardee talk presented at Nano Korea 2021, Gyeonggi-do, South Korea, Jul. 2021

● D. K. Ko; S. B. Hafiz; M. M. Al Mahfuz; E. Espin, 239th ECS Meeting with the 18th International Meeting on Chemical Sensors (IMCS), "Thermal-Infrared Quantum Dot Technology: Advances in Materials Design and Device Structure," oral

● "Infrared Colloidal Quantum Dot Based Nanoelectronics and Nano-optoelectronics", invited talk presented at 236th Electrochemical Society (ECS) Meeting, Atlanta, GA, Oct. 2019

● "Colloidal Quantum Dot-Based Mid-Wavelength Infrared Photodetectors", invited talk presented at US-Korea Conference on Science, Technology, and Entrepreneurship, Chicago, IL, August 2019

● S. Hafiz; M. Scimeca; P. Zhao; A. Sahu; D. -K. Ko, 19th IEEE International Conference on Nanotechnology (IEEE-NANO), "Silver Selenide Colloidal Quantum Dots for Low-Cost Mid-Wavelength Infrared Optoelectronics," oral

● D. -K. Ko; A. Sahu; S. Hafiz; M. Scimeca; P. Zhao, MRS, Spring 2019, "Mid-Infrared Silver Chalcogenide Colloidal Quantum Dots and Devices," oral

● "Photoconductive Photodetectors Based on Thermal Infrared Colloidal Quantum Dots", invited talk presented at US-Korea Conference on Science, Technology, and Entrepreneurship, Queens, NY, August 2018

● "Nanocomposites of Colloidal Nanocrystals and Cellulose For Paper-Based Thermoelectric Energy Harvesting Modules", invited talk presented at US-Korea Conference on Science, Technology, and Entrepreneurship, Queens, NY, August 2018

● "Colloidal Nanocrystals for Advanced Direct Energy Conversion Devices", invited talk presented at Center for Functional Nanomaterials, Brookhaven National Laboratory, January 2014

● D. -K. Ko; S. K. Suh; C. M. Chuang; P. R. Brown; M. G. Bawendi; V. Bulović, MRS, Spring 2014, "Improving the Quantum Dot Solar Cell Performance using Metal Salt Treatment," oral

● D. -K. Ko; P. R. Brown; V. Bulović; M. G. Bawendi, MRS, Spring 2013, "p-i-n Heterojunction Quantum Dot Solar Cells," oral

● D. -K. Ko; G. Hwang; R. E. Correa; G. J. Supran; V. Bulović; M. G. Bawendi, MRS, Spring 2013, "Binary Nanoparticle Superlattices Formed From Highly Luminescent Core-Shell Quantum Dots and Their Photoluminescence Properties," poster

● "Energy Transport and Conversion in Semiconductor Nanocrystal Solids", invited talk presented at Molecular Foundry, Lawrence Berkeley National Laboratory, August 2011

● "Energy Transport and Conversion in Semiconductor Nanocrystal Solids", invited talk presented at Center for Nanoscale Science and Technology, National Institute of Standards and Technology, June 2011

● C. B. Murray; D. -K. Ko; W. -K. Koh; D. Reifsnyder; Y. Kang; X. Ye; J. Chen, Abstracts of Papers of the American Chemical Society (239), March 21th 2010, "Chemical Design of Nanocrystal Assemblies for Energy Conversion"

● D. -K. Ko; C. B. Murray, MRS, Spring 2009, "Binary Nanocrystal Composite Solid for High Efficiency Thermoelectric Power Generation," oral

● D. -K. Ko; D. -H. Ha; C. B. Murray, MRS, Spring 2009, "Thermoelectric Power and Electronic Transport in Binary Nanocrystal Composite Solids," poster

● D. -K. Ko; C. B. Murray, APS, Spring 2009, Thermoelectric Materials & Phenomena, "Modular Assembly of Binary Nanocrystal Composite Solid for High Efficiency Thermoelectric Power Generation," oral

● D. -K. Ko; C. B. Murray, ACS, Fall 2008, Nanoscience: Characterization and Application, "Electronic Transport and Thermoelectric Power Generation in Nanocrystal Assemblies," poster

● D. -K. Ko; C. B. Murray, Gordon Research Conference, Chemistry of Electronic Material 2007, "Anomalous Solubility in Alloy Nanoparticles," poster