Publications

[48]

[47]  H. J. Jang+, G. Jeon+, K. Patel+, H. Lee, T. Kim, J. Y. Lee*, N. Y. Ha*, Hybridized Local and Charge-Transfer Excited State Emitter for Blue Organic Solid-State Laser, ACS Applied Materials & Interfaces, Vol.15, Issue 30,  36628-36635 (July 23, 2023).

[46] S. Ryu, N. Y. Ha, Y. H. Ahn, J. Y. Park, S. Lee*, Effect of Oxygen Vacancies in a Zinc Oxide Electron Transport Layer on Long-Term Degradation and Short-Term Photo-Induced Charges in the Operation Characteristics of Organic Solar Cells, ACS Applied Energy Materials, Vol.5, Issue 8,  9668-9675 (July 15, 2022).

[45] S. Ryu, N. Y. Ha, Y. H. Ahn, J. Y. Park, S. Lee*,  Light intensity dependence of organic solar cell operation and dominance switching between Shockley-Read-Hall and bimolecular recombination losses, Scientific Reports, Vol.11, 16781(1-10) (October 18, 2021).

[44] H.S. Kim, N. Y. Ha, J. Y. Park, S. Lee, D. S. Kim, Y. H. Ahn*,  Phonon-Polaritons in Lead Halide Perovskite Film Hybridized with THz Metamaterials, Nano Letters, Vol.20, No.9, 6690-6696 (August 12, 2020).

[43] S. Ryu, D. C. Nquyen, N. Y. Ha, H. J. Park, Y. H. Ahn, J. Y. Park, S. Lee*,  Light intensity-dependent variation in defect contributions to charge transport and recombination in a planar MAPbI3 perovskite solar cell, Scientific Reports, Vol.9, 19846(1-12) (December 27, 2019).

S. Ryu, D. C. Nquyen, N. Y. Ha, H. J. Park, Y. H. Ahn, J. Y. Park, S. Lee*,  Author Correction: Light intensity-dependent variation in defect contributions to charge transport and recombination in a planar MAPbI3 perovskite solar cell, Scientific Reports, Vol.10, 4317 (2020).

[42] M. H. Ann, J. Kim, M. Kim, G. Alosaimi, D. Kim, N. Y. Ha, J. Seidel, N. Park, J. S. Yun, J. H. Kim*, Device design rules and operation principles of high-power perovskite solar cells for indoor applications, Nano Energy, Vol.68, 104321 (November 23, 2019).

[41] S. Y. Kim, S. Y. Ryu, N. Y. Ha, Y. H. Ahn, J.-y. Park, and S. Lee*, Facile Fabrication of Mesoporous Photoanode for Dye-Sensitized Solar Cell by Microwave Sintering of Binder-free TiO2 Paste, Journal of Physics D: Applied Physics, Vol. 51, Number 35, 355501 (August 3, 2018).

[40] C. Lim, S. Bae, S. M. Jeong, N. Y. Ha*, Manipulation of Structural Colors in Liquid-Crystal Helical Structures Deformed by Surface Controls, ACS Applied Materials & Interfaces, Vol. 10, Issue 14, 120690-120695, (April 11, 2018) (published online 23 March 2018).

[39] K.-T. Lee, J.-Y. Jang, N. Y. Ha, S. Lee, H. J. Park*, High Performance Colorful Semitransparent Perovskite Solar Cells with Phase Compensated Microcavities, Nano Research, Vol.11, Issue 5, 2553-2561 (12 May 2018) (published online 28 October 2017).

[38] S. Joe, S. Ryu, D.C. Nguyen, J. H. Yim, H. Jeong,  N. Y. Ha, Y. H. Ahn, J.-y. Park, and S. Lee*, Contributions of poly(3-hexylthiophene) nanowires to alteration of vertical inhomogeneity of bulk-heterojunction active layers and improvements of light-harvesting and power-conversion efficiency of organic solar cells, Organic Electronics, Vol.42, 372 - 378,  (March 2017)(published online 3 January 2017). 

[37] J. H. Yim, S. Joe, S. Ryu, D.C. Nguyen, N. Y. Ha, Y. H. Ahn, J.-y. Park, and S. Lee*, True nature of active layers in organic solar cells fabricated by sequential casting of donor and acceptor layers, Physica Status Solidi-Rapid Research Letters, Vol.11, Issue 2, 1600415 (2017) (published online 23 December 2016).

[36] D. C. Nguyen, S. Joe, N. Y. Ha, H. J. Park, J.-Y. Park, Y. H. Ahn, and S. Lee*, Hole-extraction layer dependence of defect formation and operation of planar CH3NH3PbI3 perovskite solar cells, Physica Status Solidi-Rapid Research Letters, Vol.11, Issue 2, 1600395 (2017) (published online 23 December 2016).

[35] T. Park, S. Bae, and N. Y. Ha*, Widely tunable lasing with lowered threshold in a two-dimensional indium-tin-oxide distributed-feedback structure, Optical Materials Express, Vol. 6, No.11, 3676-3682 (1 November 2016).

[34] U. Kwon, M. M. Hasan, W. Yin, D. Kim, N. Y. Ha, S. Lee, T. K. Ahn, and H. J. Park*, Investigation into the advantages of pure perovskite film without PbI2 for high performance solar cell, Scientific Reports, Vol. 6, 35994 (1-8) (27 October 2016).

[33] U. Kwon, B. -G. Kim, D. C. Nquyen, J. -H. Park, N. Y. Ha, S. -J. Kim, S. H. Ko, S. Lee*, D. Lee*, and H. J. Park*, Solution-processible crystalline NiO nanoparticles for high-performance planar perovskite photovoltaic cells, Scientific Reports, Vol. 6, 30759 (1-10) (28 July 2016).

[32]  K. W. Yoon and N. Y. Ha*, Electrically tunable liquid crystal laser using a nanoimprinted indium-tin-oxide electrode as a distributed feedback resonator, Optics Express, Vol. 24, No.1, 516-521 (11 January 2016).

[31] S. M. Jeong*, J. -H. Kim, S. Song, J. Seo, J. -I. Hong, N. Y. Ha, H. Takezoe, J. Jeong, and H. Kim, Conductive, flexible transparent electrodes based on mechanically rubbed nonconductive polymer containing silver nanowires, RSC Advances, Vol.5, Issue 63, 51086-51091 (June 2, 2015). 

[30] S. Joe, J. H. Yim, S. Y. Ryu, N. Y. Ha, Y. H. Ahn, J.-Y. Park, and S. Lee*, Universal Efficiency Improvement in Organic Solar Cells Based on a Poly(3-hexylthiophene) Donor and an Indene-C60 Bisadduct Acceptor with Additional Donor Nanowires, ChemPhysChem, Vol. 16, Issue 6, 1217-1212 (April 27, 2015).

[29] S. M. Jeong*, S. Song, S. -K. Lee, and N. Y. Ha, Color Manipulation of Mechanoluminescence from Stress-Activated Composite Films, Advanced Materials, Vol. 25, Issue 43, 6194 - 6200 (Nobember 20, 2013) (published online August 21, 2013) (Front Cover Article).

[28] S. H. Lee and N. Y. Ha*, Nanostructured indium-tin-oxide films fabricated by all-solution processing for functional transparent electrodes, Optics Express, Vol. 19, No.22, 21803 (24 October 2011).

[27] S. H. Lee and N. Y. Ha*, Sol-gel substrates with engineered multiple-photonic-band-gaps for full-colored photonic devices, Small,  Vol.7, Issue 19, 2704 (4 October 2011) (Frontispiece).

[26] N. Y. Ha*, S. M. Jeong, S. Nishimura, and H. Takezoe*, Color-temperature tunable white reflector using bichiral liquid crystal films, Optics Express, Vol.18, No.25, 26339 (6 December 2010).

[25] N. Y. Ha*, S. M. Jeong, S. Nishimura, and H. Takezoe*, Polarization-independent multiple selective reflections from bichiral liquid crystal films, Applied Physics Letters, Vol. 96, Issue 15, 153301 (1-3) (April 12, 2010). 

[24] N. Y. Ha*, S. M. Jeong, S. Nishimura, and H. Takezoe*, Color- and reflectance-tunable multiple reflectors assembled from three polymer films, Advanced Materials, Vol. 22, Issue 14, 1617 - 1621 (April 12, 2010) (published online December 28, 2009).

[23] S. M. Jeong, J. K. Kim, Y. Shimbo, F. Araoka, S. Dhara, N. Y. Ha, K. Ishikawa, H. Takezoe*, Perfluoropolymer Surface for Shock-free Homeotropic Alignment of Smectic Liquid Crystals , Advanced Materials, Vol. 22, Issue 1, 34 - 38 (Jan 5, 2010) (published online August 15, 2009) (Frontispiece). 

[22] S. M. Jeong, N. Y. Ha, M. G. Chee, F. Araoka, K. Ishikawa, H. Takezoe*, S. Nishimura, and G. Suzaki, Enhanced linearly-polarized lasing emission from nanoimprinted surface-emitting distributed feedback laser based on polymeric liquid crystals, Applied Physics Letters, Vol. 93, Issue 22, 221101 (1-3) (December 1, 2008) (Cover Article).

[21] N. Y. Ha, S. M. Jeong, S. Nishimura, G. Suzaki, K. Ishikawa, and H. Takezoe*, Simultaneous red, green, and blue lasing emissions in a single-pitched cholesteric liquid crystal system, Advanced Materials, Vol. 20, Issue 13, 2503 - 2507 (Jul 2, 2008).

[20] S. M. Jeong, N. Y. Ha, H. Takezoe*, S. Nishimura, and G. Suzaki, Polarization-tunable electroluminescence using phase retardation based on photonic bandgap liquid crystal, Journal of Applied Physics, Vol. 103, Issue 11, 113101(1-4) (June 2, 2008).

[19] S. M. Jeong, N. Y. Ha, F. Araoka, K. Ishikawa, and H. Takezoe*, Electro-tunable polarization of surface-emitting distributed feedback laser with nematic liquid crystals, Applied Physics Letters, Vol. 92, Issue 17, 171105 (1-3) (April 29, 2008).

[18] Y. Han, N. Y. Ha, A. M. Alsayed and A. G. Yodh*, Melting of two-dimensional diameter-tunable colloidal crystals, Physical Review E, Vol. 77, No. 4, 041406 (1-7) (18 April 2008). 

[17] N. Y. Ha, Y. Ohtsuka, S. M. Jeong, S. Nishimura, G. Suzaki, Y. Takanishi, K. Ishikawa, and H. Takezoe*, Fabrication of a simultaneous red-green-blue reflector using single-pitched cholesteric liquid crystals, Nature Materials, Vol. 7, Issue 1, 43-47 (January 2008) (Published online 11 November 2007). 

[16] S. -W. Choi, S. Kawauchi, N. Y. Ha, H. Takezoe*, Photoinduced chirality in azobenzene-containing polymer system, Physical Chemistry Chemical Physics, Vol. 9, Issue 28, 3671 - 3681 (28 July 2007)(Advanced article on the web 24th April 2007) (Cover Article). 

[15] S. M. Jeong, N. Y. Ha, Y. Takanishi, K. Ishikawa, H. Takezoe*, S. Nishimura, and G. Suzaki, Defect mode lasing from a double-layered dye-doped polymeric cholesteric liquid crystal films with a thin rubbed defect layer, Applied Physics Letters, Vol. 90, No. 26, 261108 (1-3) (26 June 2007). 

[14] Y. Takanishi, N. Tomoe, N. Y. Ha, T. Toyooka, S. Nishimura, K. Ishikawa, H. Takezoe*, Defect-mode lasing from a three-layered helical cholesteric liquid crystal structure, Japanese Journal of Applied Physics, Vol. 46, Issue 6A, 3510-3513 (June 6, 2007). 

[13] S. M. Jeong, Y. Ohtsuka, N. Y. Ha, Y. Takanishi, K. Ishikawa, H. Takezoe*, S. Nishimura, and G. Suzaki, Highly circularly polarized electroluminescence from organic light-emitting diodes with wide-band reflective polymeric cholesteric liquid crystal films, Applied Physics Letters, Vol. 90, Issue 21, 211106(1-3) (21 May 2007). 

[12] N. Y. Ha, Y. Takanishi, K. Ishikawa, and H. Takezoe*, Simultaneous RGB reflections from single-pitched cholesteric liquid crystal films with Fibonaccian defects, Optics Express, Vol. 15, No. 3, 1024-1029 (5 February 2007).

[11] N. Y. Ha, J. W. Wu*, and B. Park, Bandgap of a three-dimensional dyed polystyrene photonic crystal from optical absorption, Journal of the Optical Society of America B, Vol. 23, No. 5, 958-962 (May 2006). 

[10] S. -W. Choi, N. Y. Ha, K. Shiromo, N. V. S. Rao, M. K. Paul, T. Toyooka, S. Nishimura, J. W. Wu, B. Park, Y. Takanishi, K. Ishikawa, and H. Takezoe*, Photoinduced circular anisotropy in a photochromic W-shaped-molecule-doped polymeric liquid crystal film, Physical Review E, Vol. 73, No. 2, 021702 (1-6) (10 February 2006). 

[9] M. H. Song, N. Y. Ha, K. Amemiya, B. Park, Y. Takanishi, K. Ishikawa, J. W. Wu, S. Nishimura, T. Toyooka and H. Takezoe*, Defect Mode Lasing with Lowered Threshold in a 3-Layered Hetero Cholesteric Liquid Crystal Structure, Advanced Materials, Vol. 18, Issue 2, 193-197 (January 2006) (Published online December 8, 2005). 

[8] N. Y. Ha, S. H. Han, D. W. Jeon, C.-S. Jung , B. Park, H. Takezoe, and J. W. Wu*, Analysis of surface second harmonic generation by orientational distribution function in a chiral polymer film, Physical Review E, Vol. 72, No. 3, 036601 (1-10) (7 September 2005). 

[7] F. Araoka, N. Y. Ha, Y. Kinoshita, B. Park, J. W. Wu, and H. Takezoe*, Twist-grain-boundary structure in the B4 phase of a bent-core molecular system identified by second harmonic generation circular dichroism measurement, Physical Review Letters, Vol. 94, No. 13, 137801 (1-4) (7 April, 2005). 

[6] N. Y. Ha, Y. K. Woo, B. Park, H. Takezoe and J. W. Wu*, Self-assembled silica photonic crystal as a liquid crystal alignment layer and its electro-optic application in Fabry-Perot cavity structure, Advanced Materials, Vol. 16, No. 19, 1725-1729 (4 October 2004) (Inside Cover Article). 

[5] J. Hwang, N. Y. Ha, H. J. Chang, B. Park and J. W. Wu*, Enhanced optical nonlinearity near photonic bandgap edges of a cholesteric liquid crystal, Optics Letters, Vol. 29, No. 22, 2644-2646 (November 15, 2004). 

[4] H. J. Chang, N. Y. Ha, A. Kim, B. Park, J. -H. Lim, E. -J. Park, J. -H. Kim, S. -H. Lee and J. W. Wu*, Electro-optic response of an electrostatically self-assembled single polymeric monolayer in attenuated total reflection configuration, Optics Communications, Vol. 240, Issues 1-3, 29-38 (1 October 2004). 

[3] N. Y. Ha, J. W. Wu*, and B. Park, Fabrication and optical characterization of 3-D polystyrene colloidal photonic crystal, Journal of the Korean Physical Society, Vol. 45, No. 1, 108-111 (July 2004). 

[2] H. J. Chang, N. Y. Ha, A. Kim, J. Lim, B. Park, E.-J. Park, J. -H. Im, J. -H. Kim, S. -H. Lee, J. W. Wu*, Characterization of electro-optic properties of self-assembled monolayer by attenuated total reflection, Optical Materials, Vol. 21, Issues 1-3, 413-416 (January 2003) (Available online 13 November 2002). 

[1] M. J. Kim, S. H. Park, M. -Y. Jeong, A. Kim, N. Y. Ha, B. Park, J. W. Wu*, J. D. Hong, Optical characteristics of self-assembled ultrathin films of tetra-copperphthalocyanine by attenuated total reflection, Molecular Crystals and Liquid Crystals, Vol. 371, Issue 1, 163 - 166 (October 2001).