title: Tunable Ultraviolet Photoresponse in Solution-Processed p-n Junction Photodiodes Based on Transition-Metal Oxides.
abstract: Solution-processed p-n heterojunction photodiodes have been fabricated based on transition-metal oxides in which NiO and ternary Zn(1-x)Mg(x)O (x = 0-0.1) have been employed as p-type and n-type semiconductors, respectively. Composition-related structural, electrical, and optical properties are also investigated for all the films. It has been observed that the bandgap of Zn(1-x)Mg(x)O films can be tuned between 3.24 and 3.49 eV by increasing Mg content. The fabricated highly visible-blind p-n junction photodiodes show an excellent rectification ratio along with good photoresponse and quantum efficiency under ultraviolet (UV) illumination. With an applied reverse bias of 1 V and depending on the value of x, the maximum responsivity of the devices varies between 0.22 and 0.4 A/W and the detectivity varies between 0.17 × 10(12) and 2.2 × 10(12) cm (Hz)(1/2)/W. The photodetectors show an excellent UV-to-visible rejection ratio. Compositional nonuniformity has been observed locally in the alloyed films with x = 0.1, which is manifested in photoresponse and X-ray analysis data. This paper demonstrates simple solution-processed, low cost, band tunable photodiodes with excellent figures of merit operated under low bias.
authors.affiliation: †Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.|‡Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742, United States.
authors.forename: Ting
authors.initials: T
authors.lastname: Xie
authors.affiliation: †Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.|‡Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742, United States.|§Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, United States.
authors.forename: Guannan
authors.initials: G
authors.lastname: Liu
authors.affiliation: †Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.
authors.forename: Baomei
authors.initials: B
authors.lastname: Wen
authors.affiliation: †Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.|§Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, United States.
authors.forename: Jong Y
authors.initials: JY
authors.lastname: Ha
authors.affiliation: ∥Semiconductor and Dimensional Metrology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.
authors.forename: Nhan V
authors.initials: NV
authors.lastname: Nguyen
authors.affiliation: †Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.|§Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, United States.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Motayed
authors.affiliation: †Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.
authors.forename: Ratan
authors.initials: R
authors.lastname: Debnath
keywords: NiO; TMO; Zn1−xMgxO; photodetector