title: Direct formation of InN-codoped p-ZnO/n-GaN heterojunction diode by solgel spin-coating scheme.
abstract: In this work p-ZnO/n-GaN heterojunction diodes were directly formed on the Si substrate by a combination of cost-effective solgel spin-coating and thermal annealing treatment. Spin-coated n-ZnO films on InN/GaN/Si wafers were converted to p-type polarity after thermal treatment of proper annealing durations. X-ray diffraction (XRD) analysis reveals that InN-codoped ZnO films have grown as the standard hexagonal wurtzite structure with a preferential orientation in the (002) direction. The intensity of the (002) peak decreases for a further extended annealing duration, indicating the greater incorporation of dopants, also confirmed by x-ray photoelectron spectroscopy and low-temperature photoluminescence. Hall and resistivity measurements validate that our p-type ZnO film has a high carrier concentration of 3.73×10¹⁷ cm⁻³, a high mobility of 210 cm²/Vs, and a low resistivity of 0.079 Ωcm. As a result, the proposed p-ZnO/n-GaN heterojunction diode displays a well-behaving current rectification of a typical p-n junction, and the measured current versus voltage (I-V) characteristic is hence well described by the modified Shockley equation. The research on the fabrication of p-ZnO/n-GaN heterojunctions shown here generates useful advances in the production of cost-effective ZnO-based optoelectronic devices.
authors.forename: Chun-Ying
authors.initials: CY
authors.lastname: Huang
authors.forename: Ya-Ju
authors.initials: YJ
authors.lastname: Lee
authors.forename: Tai-Yuan
authors.initials: TY
authors.lastname: Lin
authors.forename: Shao-Lun
authors.initials: SL
authors.lastname: Chang
authors.forename: Jan-Tian
authors.initials: JT
authors.lastname: Lian
authors.forename: Hsiu-Mei
authors.initials: HM
authors.lastname: Lin
authors.forename: Nie-Chuan
authors.initials: NC
authors.lastname: Chen
authors.forename: Ying-Jay
authors.initials: YJ
authors.lastname: Yang
mesh_terms: D003362:Cost-Benefit Analysis; D005240:Feasibility Studies; D005708:Gallium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D012666:Semiconductors / Q000191:economics; D013696:Temperature; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D007204:Indium; C473348:gallium nitride; D005708:Gallium; C513701:indium nitride; D015034:Zinc Oxide