title: Low Dark-Current, High Current-Gain of PVK/ZnO Nanoparticles Composite-Based UV Photodetector by PN-Heterojunction Control.
abstract: We propose a solution-processable ultraviolet (UV) photodetector with a pn-heterojunction hybrid photoactive layer (HPL) that is composed of poly-n-vinylcarbazole (PVK) as a p-type polymer and ZnO nanoparticles (NPs) as an n-type metal oxide. To observe the effective photo-inducing ability of the UV photodetector, we analyzed the optical and electrical properties of HPL which is controlled by the doping concentration of n-type ZnO NPs in PVK matrix. Additionally, we confirmed that the optical properties of HPL dominantly depend on the ZnO NPs from the UV-vis absorption and the photoluminescence (PL) spectral measurements. This HPL can induce efficient charge transfer in the localized narrow pn-heterojunction domain and increases the photocurrent gain. It is essential that proper doping concentration of n-type ZnO NPs in polymer matrix is obtained to improve the performance of the UV photodetector. When the ZnO NPs are doped with the optimized concentration of 3.4 wt.%, the electrical properties of the photocurrent are significantly increased. The ratio of the photocurrent was approximately 10³ higher than that of the dark current.
authors.affiliation: School of Electronics Engineering, College of IT engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. sw3148@ee.knu.ac.kr.
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Lee
authors.affiliation: School of Electronics Engineering, College of IT engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. cha2155@naver.com.
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Cha
authors.affiliation: Department of Sensor and Display Engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. dusen2147@naver.com.
authors.forename: Kyung-Jae
authors.initials: KJ
authors.lastname: Choi
authors.affiliation: Center for Functional Devices Fusion Platform, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. bhkang@ee.knu.ac.kr.
authors.forename: Byoung-Ho
authors.initials: BH
authors.lastname: Kang
authors.affiliation: School of Electronics Engineering, College of IT engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. js1245@ee.knu.ac.kr.
authors.forename: Jae-Sung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: School of Electronics Engineering, College of IT engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. kei95304@gmail.com.
authors.forename: Sae-Wan
authors.initials: SW
authors.lastname: Kim
authors.affiliation: School of Electronics Engineering, College of IT engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. jskim5772@ee.knu.ac.kr.
authors.forename: Ju-Seong
authors.initials: JS
authors.lastname: Kim
authors.affiliation: School of Electronics Engineering, College of IT engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. hmjeong@ee.knu.ac.kr.
authors.forename: Hyun-Min
authors.initials: HM
authors.lastname: Jeong
authors.affiliation: School of Electronics Engineering, College of IT engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. gsai_anandh@yahoo.com.
authors.forename: Sai-Anand
authors.initials: SA
authors.lastname: Gopalan
authors.affiliation: Department of Electronics Engineering, Kyungil University, 50 Gamasil-Gil, Hayang-Eup, Gyeongbuk, 38428 Gyeongsan-Si, Korea. dhkwon@kiu.ac.kr.
authors.forename: Dae-Hyuk
authors.initials: DH
authors.lastname: Kwon
authors.affiliation: School of Electronics Engineering, College of IT engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea. swkang@knu.ac.kr.
authors.forename: Shin-Won
authors.initials: SW
authors.lastname: Kang
mesh_terms: D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D055668:Photochemical Processes; D011145:Polyvinyls / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D011145:Polyvinyls; C035125:poly-N-vinylcarbazole; D015034:Zinc Oxide
keywords: UV photodetector; ZnO nanoparticles; hybrid photoactive layer; pn-heterojunction