title: Suppressing spontaneous polarization of p-GaN by graphene oxide passivation: augmented light output of GaN UV-LED.
abstract: GaN-based ultraviolet (UV) LEDs are widely used in numerous applications, including white light pump sources and high-density optical data storage. However, one notorious issue is low hole injection rate in p-type transport layer due to poorly activated holes and spontaneous polarization, giving rise to insufficient light emission efficiency. Therefore, improving hole injection rate is a key step towards high performance UV-LEDs. Here, we report a new method of suppressing spontaneous polarization in p-type region to augment light output of UV-LEDs. This was achieved by simply passivating graphene oxide (GO) on top of the fully fabricated LED. The dipole layer formed by the passivated GO enhanced hole injection rate by suppressing spontaneous polarization in p-type region. The homogeneity of electroluminescence intensity in active layers was improved due to band filling effect. As a consequence, the light output was enhanced by 60% in linear current region. Our simple approach of suppressing spontaneous polarization of p-GaN using GO passivation disrupts the current state of the art technology and will be useful for high-efficiency UV-LED technology.
authors.affiliation: 1] Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon 440-746, Republic of Korea [2] Laboratoire de Nanotechnologie et d'Instrumentation Optique, Institut Charles Delaunay, CNRS-UMR 6279, Université de Technologie de Troyes, BP 2060, 10010 Troyes, France.
authors.forename: Hyun
authors.initials: H
authors.lastname: Jeong
authors.affiliation: Graphene Hybrid World Class Laboratory, Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute, Changwon 641-120, Republic of Korea.
authors.forename: Seung Yol
authors.initials: SY
authors.lastname: Jeong
authors.affiliation: Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Doo Jae
authors.initials: DJ
authors.lastname: Park
authors.affiliation: 1] Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon 440-746, Republic of Korea [2] Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Hyeon Jun
authors.initials: HJ
authors.lastname: Jeong
authors.affiliation: Graphene Hybrid World Class Laboratory, Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute, Changwon 641-120, Republic of Korea.
authors.forename: Sooyeon
authors.initials: S
authors.lastname: Jeong
authors.affiliation: Graphene Hybrid World Class Laboratory, Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute, Changwon 641-120, Republic of Korea.
authors.forename: Joong Tark
authors.initials: JT
authors.lastname: Han
authors.affiliation: Graphene Hybrid World Class Laboratory, Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute, Changwon 641-120, Republic of Korea.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Jeong
authors.affiliation: Graphene Hybrid World Class Laboratory, Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute, Changwon 641-120, Republic of Korea.
authors.forename: Sunhye
authors.initials: S
authors.lastname: Yang
authors.affiliation: 1] Graphene Hybrid World Class Laboratory, Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute, Changwon 641-120, Republic of Korea [2] Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Ho Young
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Graphene Hybrid World Class Laboratory, Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute, Changwon 641-120, Republic of Korea.
authors.forename: Kang-Jun
authors.initials: KJ
authors.lastname: Baeg
authors.affiliation: Department of Physics and Division of Energy Systems Research, Ajou University, Suwon 443-749, Republic of Korea.
authors.forename: Sae June
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Physics and Division of Energy Systems Research, Ajou University, Suwon 443-749, Republic of Korea.
authors.forename: Yeong Hwan
authors.initials: YH
authors.lastname: Ahn
authors.affiliation: School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Suh
authors.affiliation: Graphene Hybrid World Class Laboratory, Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute, Changwon 641-120, Republic of Korea.
authors.forename: Geon-Woong
authors.initials: GW
authors.lastname: Lee
authors.affiliation: 1] Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon 440-746, Republic of Korea [2] Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Lee
authors.affiliation: 1] Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon 440-746, Republic of Korea [2] Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Mun Seok
authors.initials: MS
authors.lastname: Jeong