Publications
42. Periyayya Uthirakumar, S. Senthilarasu, Chang-Hee Hong, “Different Types of Zinc Oxide nanomaterials for Dye Sensitized Solar Cells Applications”, Physica E: Low dimensional systems and nanostructures - Available online - 12 June 2011.
41. Ji Hye Kang, Jae Hyoung Ryu, Hyun Kyu Kim, Hee Yun Kim, Nam Han, Mi So Lee, Young Jae Park, Periyayya Uthirakumar, Volodymyr V. Lysak, Chang-Hee Hong, “Enhancement of light output power in GaN-based light-emitting diodes using indium tin oxide films with nanoporous structures” Thin Solid Films, Available online - 26 May 2011.
40. Periyayya Uthirakumar, Ji Hye Kang, Beo Deul Ryu, and Chang-Hee Hong. “Improved Light Extraction Efficiency of GaN-based Light Emitting Diodes using One and Two Interfaces of ITO/ZnO Layer Texturing”, Materials Science and Semiconductor Processing –Available online- 9 March 2011.
39. Hyun Kyu Kim, Hyung Gu Kim, Kim, H.Y., Ryu, J.H., Ji Hye Kang, Nam Han, Kwon, B.J., Periyayya Uthirakumar, Han, M.S., Kang, S.H., Chang-Hee Hong, “Light output power enhancement of GaN-based light emitting diodes with periodic deflector embedded on the wet etch patterned sapphire substrate” Japanese Journal of Applied Physics, 50 (4 PART 1), (2011) 042102.
38. Beo Deul Ryu, Periyayya Uthirakumar, Ji Hye Kang, Bong Jun Kwon, S. Chandramohan, Hyun Kyu Kim, Hee Yun Kim, Jae Hyoung Ryu, Hyung Gu Kim, and Chang-Hee Hong, “Enhanced light output power of GaN-based light-emitting diodes by nano-rough indium tin oxide film using ZnO nanoparticles” Journal of Applied Physics, 109 (May 2011), 093116-093120.
[News archived in semiconductor-today magazine: http://www.semiconductor-today.com/news_items/2011/MAY/CNU_300511.html].
37. Ji Hye Kang, Jae Ryu Park, Hyun Kyu Kim, Hee Yun Kim, Nam Han, Young Jae Park, Periyayya Uthirakumar, and Chang-Hee Hong, “Comparison of various surface textured layer in InGaN LEDs for high light extraction efficiency” Optics Express, 19 (4) (February 2011) 3637-3646.
36. S. Chandramohan, Beo Deul Ryu, Periyayya Uthirakumar, Ji Hye Kang, Hyun Kyu Kim, Hyung Gu Kim, Chang-Hee Hong “Tuning the spectrometric properties of white light by surface plasmon effect using Ag nanoparticles in a colour converting light-emitting diode” Solid-State Electronics, 57 (1) (March 2011), 90-92.
35. Mi So Lee, Hyung Gu Kim, Ji Hye Kang, Jae Hyoung Ryu, Hyun Kyu Kim, Hee Yun Kim, Periyayya Uthirakumar, and Chang-Hee Hong “Enhancement of light output power and modification of beam profile in InGaN/GaN light emitting diodes with micro polygon column shaped transparent” Japanese Journal of Applied Physics, 49 (11) (November 2010) 112101.
34. Hyung Gu Kim, Hyun Kyu Kim, Hee Yun Kim, Hyun Jeong, S. Chandramohan, Periyayya Uthirakumar, Mun Seok Jeong, Jeong-Sik Lee, Eun-Kyung Suhand Chang-Hee Hong, “Enhanced air-cavity effect of periodically oriented embedded air protrusions for high-efficiency InGaN/GaN light-emitting diodes” Optics Letters, 35 (18) (August 2010) 3012-3014.
33. Periyayya Uthirakumar, Ji Hye Kang, Hyung Gu Kim, and Chang-Hee Hong. “Impact of Layer Thickness and Light Transmission of ZnO Nanomaterials on GaN-Based Light Emitting Diodes”, Vacuum, 85 (August 2010) 198-202. Top 25 (15th) Hottest Articles in Physics and Astronomy-Vacuum in Science direct: October - December 2010.
32. P.Michael S.L. Shanthi, R.V. Mangalaraja, Periyayya Uthirakumar, S. Velmathi, T. Balasubramanian, M. Ashok “Synthesis and characterization of porous shell-like nano hydroxyapatite using cetrimide as template”, Journal of Colloid and Interface Science, 350 (1) (October 2010) 39-43.
31. Jae Hyoung Ryu, S. Chandramohan, Hyung Gu Kim, Hee Yun Kim, Hyun Kyu Kim, Nam Han, Ji Hye Kang, Periyayya Uthirakumar, Chang -Hee Hong, Hyun Kyong Cho, Hyun Don Song, Ho-Ki Kwon, “Effect of Ridge growth on water bowing and light extraction efficiency of vertical GaN-based light emitting diodes”, Japanese Journal of Applied Physics, 49 (July 2010) 072102-05.
30. Hyun Kyu Kim, Hyung Gu Kim, Hee Yun Kim, Jae Hyoung Ryu, Ji Hye Kang, Nam Han, Periyayya Uthirakumar and Chang-Hee Hong: “Enhanced Light Output Power of GaN-based Light Emitting Diodes with Overcut Sideholes formatted by Wet Etching”, Solid State Electronics, 54 (5) (May 2010) 575-578.
29. Periyayya Uthirakumar, Ji Hye Kang, Beo Deul Ryu, Hyung Gu Kim, Hyun Kyu Kim, and Chang-Hee Hong. “Nanoscale ITO/ZnO Layer-Texturing for High-Efficiency InGaN/GaN Light Emitting Diodes”, Journal of Materials Science and Engineering B, 166 (February 2010) 230-234.
28. Hyung Gu Kim, Hee Yun Kim, Hyun Kyu Kim, Jae Hyoung Ryu, Ji Hye Kang, Nam Han, Periyayya Uthirakumar and Chang-Hee Hong: “Impact of two-floor air prism arrays as an embedded reflector for enhancing the output power of InGaN/GaN light emitting diodes”, Applied Physics Letters, 95 (December 2009) 221110-221113.
27. Hyung Gu Kim, Hyun Kyu Kim, Hee Yun Kim, Jae Hyoung Ryu, Ji hae Kang, Nam Han, Periyayya Uthirakumar and Chang-Hee Hong: “Enhanced Light Output Power of InGaN/GaN Light Emitting Diodes with Embedded Air Prisms”, Electrochemical and Solid-State Letters, 13 (2) (January 2010) H42-H44.
26. Ji Hye Kang, Hyung Gu Kim, Jae Ryu Park, Hyun Kyu Kim, Hee Yun Kim, Mi So Lee, Young Jae Park, Periyayya Uthirakumar, and Chang-Hee Hong, “Enhancement of light output power in InGaN/GaN LEDs with nanoroughed hemispherical Indium Tin Oxide transparent ohmic contacts”, Electrochemical and Solid-State Letters,13 (2) (January 2010) D1-D3.
25. Periyayya Uthirakumar, Hyung Gu Kim, and Chang-Hee Hong “Zinc Oxide Nanostructures Derived from a Simple Solution Method for Solar Cells and LEDs”, Chemical Engineering Journal, 155 (December 2009) 910-915. [Times Cited: 1]
24. Ji Hye Kang, Hyung Gu Kim, Hyun Kyu Kim, Hee Yun Kim, Jae Hyoung Ryu, Periyayya Uthirakumar, Nam Han, and Chang-Hee Hong, “Improvement of light output power in InGaN/GaN Light-Emitting Diodes with a nanotextured GaN surface using Indium Tin Oxide nanospheres”, Japanese Journal of Applied Physics, 48 (October 2009) 102104-102108. [Times Cited: 2]
23. Periyayya Uthirakumar and Chang-Hee Hong, “Effect of Annealing Temperature and pH on the Morphology and Optical Properties of Highly Dispersible ZnO nanoparticles”, Material Characterization, 60(11) (November 2009) 1305-1310.
22. Periyayya Uthirakumar, H-Nam, Seung Hee Woo, Eun-Kyung Suh and Chang-Hee Hong “A Catalyst Free Approach to Prepare Nano to Microstructures of GaN from a Single Molecular Complex Precursor”, Journal of Korean Physical Society, 55 (July 2009) 59-63.
21. Hyung Gu Kim, Hyun Kyu Kim, Hee Yun Kim, Jae Hyoung Ryu, Ji hye Kang, Nam Han, Periyayya Uthirakumar, Dong Hyun Yu, and Chang-Hee Hong “InGaN/GaN Light-Emitting Diodes with Overcut-Shaped Periodic Microstructures Formed by Wet Etching Process” Electrochemical and Solid-State Letters, 12 (8) (May 2009) H299-H301. [Times Cited: 1]
20. Seung Hun Eom, S. Senthilarasu, Periyayya Uthirakumar, Sung Cheol Yoon, Jongsun Lim, Changjin Lee, Hyun Seok Lim, J. Lee, Soo-Hyoung Lee “ Polymer solar cells based on inkjet-printed PEDOT:PSS layer”, Organic Electronics, 10 (3) (May 2009) 536-542. [Times Cited: 2]
19. G. Gnana Kumar, Periyayya Uthirakumar, Kee Suk Nahm and R. Nimma Elizabeth: “Fabrication and electro chemical properties of poly vinyl alcohol/para toluene sulfonic acid membranes for the applications of DMFC”, Solid State Ionics, 180 (2-3) (March 2009) 282-287. [Times Cited: 2]
18. Periyayya Uthirakumar, H-Nam, Seung Hee Woo, Eun-Kyung Suh and Chang-Hee Hong “Synthesis and Optical Properties of Sword-like GaN nanorods clusters”, Current Applied Physics, 9(1)Supplement 1 (January 2009) S114-S117. [Times Cited: 1]
17. Periyayya Uthirakumar, Eun-Kyung Suh, and Chang-Hee Hong: “The Impact of ZnO interlayer on the Growth and Morphology of Broom-like Single Crystalline GaN”, Journal of Nanoscience and Nanotechnology, 8 (October 2008) 5351–5355. [Times Cited: 1]
16. Periyayya Uthirakumar, Eun-Kyung Suh, and Chang-Hee Hong: “Growth, Morphology and Optical properties of Tris(8-hydroxyquinoline)aluminum/Zinc oxide Hybrid Nanowires”, Journal of Luminescence, 128 (10) (October 2008) 1629-1634. [Times Cited: 2]
15. Seung Hun Eom, S. Senthilarasu, Periyayya Uthirakumar, Chang-Hee Hong, Youn-Sik Lee, Jongsun Lim, Sung Cheol Yoon, Changjin Lee and Soo-Hyoung Lee: “Preparation and characterization of nano-scale ZnO as a buffer layer for inkjet printing of silver cathode in polymer solar cells”, Solar Energy Materials and Solar Cells, 92 (5)(May 2008) 564-570. Top 25 (4th) Hottest Articles in Science Direct: January - March 2008 [Times Cited: 7]
14. Periyayya Uthirakumar, Youn-Sik Lee, Eun-Kyung Suh, and Chang-Hee Hong: “Hybrid Fluorescent Polymer-Zinc oxide Nanoparticles: Improved Efficiency for Luminescence Conversion LED”, Journal of Luminescence, 128 (3) (March 2008) 287-296. Top 25 (1st) Hottest Articles in Physics and Astronomy-Journal of Luminescence in Science direct: January - March 2008 [Times Cited: 10]
13. Periyayya Uthirakumar, Eun-Kyung Suh, and Chang-Hee Hong: “Effect of Zinc oxide Incorporation on the Morphology of Tris(8-hydroxyquinoline)aluminum / Zinc oxide Hybrid Nanomaterials”, Thin solid films, 516 (21)(September 2008, 7299-7305.
12. Periyayya Uthirakumar, Eun-Kyung Suh, Chang-Hee Hong and Youn-Sik Lee: “Preparation of exfoliated high-impact polystyrene/MMT nanocomposites via in situ polymerization under controlling viscosity of the reaction medium”, Polymer Composites, 29 (2) (February 2008), 142-148.
11. B. Karunagaran, Periyayya Uthirakumar, S.J. Chung, S. Velumani and E.-K. Suh: “TiO2 thin film gas sensor for monitoring ammonia”, Materials Characterization, 58 (8-9) (Aug-Sep 2007), 680-684. Top 25 (1st) Hottest Articles in Materials science-Materials Characterization in Science direct: July - September 2007. [Times Cited: 15]
10. Periyayya Uthirakumar, Chang-Hee Hong, Eun-Kyung Suh, and Youn-Sik Lee: “A Yellow Light-Emitting Polymer Bearing Fluorescein Dye Units: Photophysical Property and Application as Luminescence Converter of a Hybrid LED”, Reactive and functional polymer, 67 (4) (April 2007) 341-347. [Times Cited: 3]
9. Periyayya Uthirakumar, Youn-Sik Lee, Eun-Kyung Suh, and Chang-Hee Hong: “Nano crystalline ZnO particles: Low temperature solution approach from a single molecular precursor”, Journal of Crystal Growth, 304 (1) (June 2007), 150-157. Top 25 (3rd ) Hottest Articles in Science direct: April - June 2007 [Times Cited: 4]
8. Periyayya Uthirakumar, Chang-Hee Hong, Eun-Kyung Suh, and Youn-Sik Lee: “Novel Fluorescent Polymer-Zinc oxide hybrids for Bright and Efficient White Light Emitting Diodes”, Chemistry of Materials, 18 (October 2006) 4990-4992. Most-Accessed Articles: October-December, 2006. [Times Cited: 8]
7. Periyayya Uthirakumar, Eun-Kyung Suh, Chang-Hee Hong and Youn-Sik Lee: “Preparation and Photophysical Properties of Organic Fluorescent Polymer and their Nanoparticles”, Journal of Applied Polymer Science, 102 (December 2006) 5344-5350. [Times Cited: 4]
6. Periyayya Uthirakumar, Youn-Sik Lee, Eun-Kyung Suh, and Chang-Hee Hong: “ZnO Nanoballs Synthesized from a Single Molecular Precursor via Non-Hydrolytic Solution Route Without Assistance of Base, Surfactant, and Template etc”, Physics Letters A, 359 (3) (November 2006) 223-226. [Times Cited: 11]
5. Periyayya Uthirakumar, Eun-Kyung Suh, Chang-Hee Hong and Youn-Sik Lee: “Synthesis and Characterization of Polyesters Containing Fluorescein Dye Units”, Polymer, 46 (June 2005) 4640-4646. [Times Cited: 10]
4. Periyayya Uthirakumar, Yoon Bong Hahn, Kee Suk Nahm, and Youn-Sik Lee: “Exfoliated High Impact Polystyrene/MMT Nanocomposites using Anchored Cationic Radical Initiator-MMT Hybrid”, European Polymer Journal, 41 (July 2005) 1582-1588. [Times Cited: 16]
3. Periyayya Uthirakumar, Song Ming Ki, Chang Woon Nah, and Youn-Sik Lee: “Preparation and Characterization of Exfoliated Polystyrene/Clay Nanocomposites using a Cationic Radical Initiator-MMT Hybrid”, European Polymer Journal, 41(2) (February 2005) 211-217. [Times Cited: 25]
2. Periyayya Uthirakumar, Kee Suk Nahm, Yoon Bong Hahn, and Youn-Sik Lee: “Preparation of Polystyrene/Montmorillonite Nanocomposites using a New Radical Initiator-Montmorillonite Hybrid via in-situ Intercalative Polymerization”, European Polymer Journal, 40(11) (November 2004) 2437-2444. Top 25 (6th) Hottest Articles in Chemistry-European Polymer Journal in Science direct: October - December 2004. [Times Cited: 32]
1. Periyayya Uthirakumar, Cheol-Ju Kim, Kee Suk Nahm, Yoon Bong Hahn, and Youn-Sik Lee: “Preparation and Characterization of New Difunctional Cationic Radical Initiator-Montmorillonite Hybrids”, Colloids and Surfaces, A: Physiochem and Eng. Aspects, 247(1-3) (October 2004) 69-75. [Times Cited: 8]
