title: Tunable p-type conductivity and transport properties of AlN nanowires via Mg doping.
abstract: Arrays of well-aligned AlN nanowires (NWs) with tunable p-type conductivity were synthesized on Si(111) substrates using bis(cyclopentadienyl)magnesium (Cp(2)Mg) vapor as a doping source by chemical vapor deposition. The Mg-doped AlN NWs are single-crystalline and grow along the [001] direction. Gate-voltage-dependent transport measurements on field-effect transistors constructed from individual NWs revealed the transition from n-type conductivity in the undoped AlN NWs to p-type conductivity in the Mg-doped NWs. By adjusting the doping gas flow rate (0-10 sccm), the conductivity of AlN NWs can be tuned over 7 orders of magnitude from (3.8-8.5) × 10(-6) Ω(-1) cm(-1) for the undoped sample to 15.6-24.4 Ω(-1) cm(-1) for the Mg-doped AlN NWs. Hole concentration as high as 4.7 × 10(19) cm(-3) was achieved for the heaviest doping. In addition, the maximum hole mobility (∼6.4 cm(2)/V s) in p-type AlN NWs is much higher than that of Mg-doped AlN films (∼1.0 cm(2)/V s). (2) The realization of p-type AlN NWs with tunable electrical transport properties may open great potential in developing practical nanodevices such as deep-UV light-emitting diodes and photodetectors.
authors.affiliation: Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, People's Republic of China.
authors.forename: Yong-Bing
authors.initials: YB
authors.lastname: Tang
authors.forename: Xiang-Hui
authors.initials: XH
authors.lastname: Bo
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Cao
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Chen
authors.forename: Hai-Sheng
authors.initials: HS
authors.lastname: Song
authors.forename: Chao-Ping
authors.initials: CP
authors.lastname: Liu
authors.forename: Tak-Fu
authors.initials: TF
authors.lastname: Hung
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Hui-Ming
authors.initials: HM
authors.lastname: Cheng
authors.forename: Igor
authors.initials: I
authors.lastname: Bello
authors.forename: Shuit-Tong
authors.initials: ST
authors.lastname: Lee
authors.forename: Chun-Sing
authors.initials: CS
authors.lastname: Lee
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D004579:Electron Transport; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008274:Magnesium / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012666:Semiconductors; D014173:Transistors, Electronic
chemical_list: D017607:Aluminum Compounds; C052045:aluminum nitride; D008274:Magnesium