Tuning of electrical charging effects for ferromagnetic Mn-doped ZnO nanocrystals embedded into a SiO{sub 2} layer fabricated by KrF excimer laser irradiation

Journal Article · Wed Jul 15 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3176933· OSTI ID:21359326

Lee, Sejoon; Kim, Deuk Young; Won Kang, Tae ^[1]; Cho, Hyung Koun ^[2]

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1. Quantum-functional Semiconductor Research Center, Dongguk University, Seoul 100-715 (Korea, Republic of)
2. School of Advanced Materials Science and Engineering, Sungkyunkwan University, Gyeong-Gi 440-746 (Korea, Republic of)

The ZnMnO nanocrystals were formed by the laser irradiation of the sputter-deposited ZnMnO ultrathin layer using a 248 nm KrF excimer laser, and the size and density of the nanocrystals were observed to be controllable by modulations of either the energy density or the frequency of the irradiated pulsed-laser beam. Metal-oxide-semiconductor capacitors fabricated using ZnMnO nanocrystals clearly showed the electrical charging effect, and it was observed that the memory window depends on the size and density of nanocrystals. For measurements of the spontaneous magnetization, ZnMnO nanocrystals showed to have room-temperature ferromagnetism with M{sub r} of approx1.5 emu/cm{sup 3} and H{sub c} 167 Oe. By using ferromagnetism in ZnMnO nanocrystals, tuning of the memory window was demonstrated. Namely, it was clearly observed that the flat-band voltage shift of approx1.25 V can be modulated to be approx0.8 V by applying the magnetic field. This is attributed to the modulation of probabilities for tunneling events due to the increased magnetoelectrical repulsion between spin-polarized carriers in ZnMnO dilute magnetic semiconductor nanocrystals and unpolarized carriers in p-Si under the magnetic field. These results suggest that ZnMnO nanocrystals can be used for spin-functional memory devices.

• OSTI ID: 21359326
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 2; Other Information: DOI: 10.1063/1.3176933; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
CAPACITORS
DEPOSITION
DOPED MATERIALS
ELECTRIC POTENTIAL
ELECTRICAL PROPERTIES
ENERGY DENSITY
FABRICATION
FERROMAGNETIC MATERIALS
FERROMAGNETISM
KRYPTON FLUORIDE LASERS
LASER RADIATION
LAYERS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETIC SEMICONDUCTORS
MAGNETIZATION
NANOSTRUCTURES
SEMICONDUCTOR LASERS
SILICON OXIDES
SPIN ORIENTATION
SPUTTERING
TEMPERATURE RANGE 0273-0400 K
TUNNEL EFFECT
ZINC OXIDES
CHALCOGENIDES
ELECTRICAL EQUIPMENT
ELECTROMAGNETIC RADIATION
EQUIPMENT
EXCIMER LASERS
GAS LASERS
LASERS
MAGNETIC MATERIALS
MAGNETISM
MATERIALS
ORIENTATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIATIONS
SEMICONDUCTOR DEVICES
SEMICONDUCTOR MATERIALS
SILICON COMPOUNDS
SOLID STATE LASERS
TEMPERATURE RANGE
ZINC COMPOUNDS