Nanomaterials, organic / perovskite photovoltaics, OLEDs

Ph.D (Physics), National University of Malaysia (UKM), 2017

(32) M.M. Ovhal, H.B. Lee, N. Kumar, J.-W. Oh and J.-W. Kang* “ Filamentous Virus-Templated Nickel Hydroxide Nanoplates as Novel Electrochemical Pseudocapacitor Materials” Polymer Korea. 48, 1 (2024).

(31) M.M. Ovhal, H.B. Lee, V.V. Satale, B. Tyagi, N. Kumar, S. Chowdhury and J.-W. Kang* “One-meter-long, All-3D-printed Supercapacitor Fibers based on Structurally Engineered Electrode for Wearable Energy Storage” Adv. Energy Mater. 14, 2303053 (2024).

(30) Hai Li, H.B. Lee, Jae-Wook Kang, Sooman Lim* “Three-dimensional polymer-nanoparticle-liquid ternary composite for ultrahigh augmentation of piezoelectric nanogenerators” Nano Energy, 113, 108576 (2023).

(29) W. Yang, G. Park, A. Liu, H.B. Lee, J.-W. Kang*, H. Zhu* and Y.-Y. Noh* "Fluorinated Organic A-Cation Enabling High-Performance Hysteresis-Free 2D/3D Hybrid Tin Perovskite Transistor" Adv. Funct. Mater. 33, 2303309 (2023)

(28) V.V. Satale, N. Kumar, H.B. Lee, M.M. Ovhal, S. Chowdhury, B. Tyagi, A. Mohamed, and J.-W. Kang* "Spray-Assisted Deposition of SnO2 Electron Transport Bilayer for Efficient Inkjet-Printed Perovskite Solar Cells" Inorganic Chemistry Frontier. 10, 3558–3567 (2023)

(27) S. He., H.B. Lee, K.-J. Ko, N. Kumar, J.-H. Jang, S.-O. Cho, M. Song, W. Zhou, B.-J. Lee, J.-H. Lee* and J.-W. Kang* "Optical Engineering of FAPbBr3 Nanocrystals via Conjugated Ligands for Light-Outcoupling Enhancement in Perovskite Light-Emitting Diodes" Adv. Opt. Mater. 11, 2300486 (2023)

(26) B. Tyagi, N. Kumar, H.B. Lee, M.M. Ovhal, V.V. Satale, A. Mohamed, D.-H. Kim and J.-W. Kang* “Development of high efficiency, spray-coated perovskite solar cells and modules using additive-engineered porous PbI2 films” Small Methode, 8, 2300237 (2024).

(25) N. Kumar, H.B. Lee, B. Tyagi, M.M. Ovhal, S. Cho, J.-S. Lee, J.-W. Oh, J.-W. Kang* “Spray deposited, virus-templated SnO2 mesoporous electron transport layer boosting the performance of perovskite solar cells” Solar RRL, 7, 2300065 (2023)

(24) B. Tyagi, N. Kumar, H.B. Lee, Y.M. Song, S. Cho, J. Lee, J.-W. Kang* "Compact-Porous Hole-Transport-Layer for Highly Efficient Near-Infrared Region Transparent Perovskite Solar Cells for Tandem Applications" Journal of Alloys and Compounds, 960, 170970 (2023)

(23) M.M. Ovhal, H.B. Lee, S. Boud, K.-J. Ko, W.-Y. Jin, N. Kumar, B. Tyagi, J.-W. Kang* “Flexible, stripe-patterned organic solar cells and modules based on multilayer-printed Ag fibers for smart textile applications” Materials Today Energy, 34, 101289 (2023)

(22) H.B. Lee, N. Kumar, S. Cho, S. Hong, H.H. Lee, H.J. Kim, J.-S. Lee, J.-W. Kang* “Intercalation of Ammonium Cationic Ligands Enabled Grain Surface Passivation in Sequential-Deposited Perovskite Solar Cells” Adv. Energy & Sustainability Res. 4, 2200128 (2023).

(21) H.B. Lee, R. Sahani, V. Devaraj, N. Kumar, B. Tyagi, J.-W. Oh, J.-W. Kang* “Complex Additive-Assisted Crystal Growth and Phase Stabilization of α-FAPbI3 Film for Highly Efficient, Air-Stable Perovskite Photovoltaics” Adv. Mater. Interface 10, 2201658 (2023).

(20) S. He, H.B. Lee, N. Kumar, K.-J. Ko, M. Song, W. Kim, J.-W. Kang* "Realizing Full-color Perovskite Quantum Dots Light-Emitting Diodes via Contemporary Surface Ligand/Anion Engineering" Mat. Today Chem 26, 101012 (2022)

(19) B. Tyagi, H.B. Lee, N. Kumar, W.-Y. Jin, K.-J. Ko, M.M. Ovhal, R. Sahani, H.-J. Jung, J. Seo, J.-W. Kang* “High-performance, large-area semitransparent and tandem perovskite solar cells featuring highly scalable a-ITO/Ag mesh 3D top electrodes” Nano Energy 95, 106978 (2022).

(18) N. Kumar, H.B. Lee, R. Sahani, B. Tyagi, S. Cho, J.-S. Lee, J.-W. Kang* “Room-Temperature Spray Deposition of Large-area SnO2 Electron Transport Layer for High Performance, Stable FAPbI3-based Perovskite Solar Cells” Small Methods 6, 2101127 (2022).

(17) H.B. Lee, N. Kumar, V. Devaraj, K.-J. Ko, S. He, B. Tyagi, J.-W. Oh*, J.-W. Kang* “Trifluoromethyl-group bearing, hydrophobic bulky cations as defect passivators for highly efficient, stable perovskite solar cells” Solar RRL 5, 2000589 (2021).

(16) M.M. Ovhal, N. Kumar, H.B. Lee, B. Tyagi, K.-J. Ko, S. Boud, J.-W. Kang* “Roll-to-Roll 3D-Printing of Flexible, Transparent, All-Solid-State Supercapacitor” Cell Reports Physical Science 2, 100562 (2021).

(15) S. He, N. Kumar, H.B. Lee, K.-J. Ko, Y.-J. Jung, J.I. Kim, S. Bae, J.-H. Lee*, J.-W. Kang* “Tailoring the Refractive Index of CsPbBr3 Quantum Dots via Alkyl Cation-Engineering for Efficient Perovskite Light-Emitting Diodes” Chem. Eng. J. 425, 130678 (2021).

(14) H.B. Lee, N. Kumar, B. Tyagi, S. He, R. Sahani, J-W Kang* “Bulky Organic Cations Engineered Lead-halide Perovskites: A Review on Dimensionality and Optoelectronic Applications” Mat. Today Energy. 21, 100759 (2021).

(13) K.-J. Ko, S.-R. Shin, H.B. Lee, E. Jeong, Y.J. Yoo, H.M. Kim, Y. M. Song*, J. Yun*, J.-W. Kang* “Fabrication of an oxide/metal/oxide structured electrode integrated with anti-reflective film to enhance performance in flexible organic light-emitting diodes” Mat. Today Energy. 20, 100704 (2021).

(12) W.-J. Jin, M.M. Ovhal, H.B. Lee, B. Tyagi and J.-W. Kang* “Scalable, All-Printed Photocapacitor Fibers and Modules based on Metal-Embedded Flexible Transparent Conductive Electrodes for Self-Charging Wearable Applications” Adv. Energy. Mater. 11, 2003509 (2021).

(11) H.B. Lee, N. Kumar, B. Tyagi and J.-W. Kang* “Dimensionality and defect engineering using fluoroaromatic cations for efficiency and stability enhancement in perovskite photovoltaics” RRL Solar 5, 2000589 (2021).

(10) K.-J. Ko, H.B. Lee and J.-W. Kang* "Flexible, wearable organic light-emitting fibers based on PEDOT:PSS/Ag-fiber embedded hybrid electrodes for large-area textile lighting" Adv. Mater. Tech. 5, 2000168 (2020).

(9) H.B. Lee, N. Kumar, M.M. Ovhal, Y.J. Kim, Y.M. Song and J.-W. Kang* "Dopant-free, amorphous-crystalline heterophase SnO2 electron transport bilayer enables >20% efficiency in triple-cation perovskite solar cells" Adv. Funct. Mater. 30, 2001559 (2020).

(8) B.Tyagi, H.B. Lee, N. Kumar, and J.-W. Kang* "Double-halide interfacial engineered perovskite solar cells demonstrating outstanding performance and stability" ACS Appl. Energy Mater 3, 8595 (2020).

(7) H.B. Lee, W.-G. Kim, M. Lee, J.-M. Lee, S. He, N. Kumar, V. Devaraj, E.J. Choi, I. Jeon, M. Song, J.-W. Oh* and J.-W. Kang* "Gap-plasmon of virus-templated biohybrid nanostructures uplifting the performance of organic optoelectronic devices" Adv. Opt. Mater. 8, pp. 1902080 (2020)

(6) N. Kumar, H.B. Lee, S. Hwang and J.-W. Kang* "Large-area, green solvent spray deposited nickel oxide films for scalable fabrication of triple-cation perovskite solar cells" J. Mater. Chem. A 8, pp.3357 (2020).

(5) H.B. Lee, M.-K. Jeon, N. Kumar, B. Tyagi, and J.-W. Kang* "Boosting the efficiency of SnO2-triple cation perovskite system beyond 20% using non-halogenated antisolvent" Adv. Funct. Mater. 29, 1903213 (2019).

(4) H.B. Lee, W.-Y. Jin, M.M. Ovhal, N. Kumar, J.-W. Kang* "Flexible transparent conducting electrodes based on metal mesh for organic optoelectronic device applications: A Review" J. Mater. Chem. C 7, pp.1087-1110 (2019).

(3) N. Kumar, H.B. Lee, S. Hwang, T.-W. Kim*, J.-W. Kang* "Fabrication of plasmonic gold-nanoparticle-transition metal oxides thin films for optoelectronic applications" J. Alloys Compd. 775, pp.39-50 (2019).

(2) K.-J. Ko, H.B. Lee, H.M. Kim, G.J. Lee, S.-R. Shin, N. Kumar, Y.M. Song*, J.-W. Kang*, "High-performance, color-tunable fiber shaped organic light-emitting diodes" Nanoscale 10, pp.16184-16192 (2018).

(1) S.-R. Shin, H.B. Lee, W.-Y. Jin, K.-J. Ko, S. Park, S. Yoo,* J.-W. Kang*, "Improving light extraction of flexible OLEDs using a mechanically robust Ag mesh/ITO composite electrode and microlens array" J. Mater. Chem. C 6, pp.5444-5452 (2018)