MAJIC-SPIN · Doped Magnetic ZnO p-n Junction Heterostructures for Nano-Spintronic Devices
FP7 — People (Marie Curie Actions)
- Duration
- 2008-07-01 → 2010-06-30
- EU contribution
- €168,824
- Participants
- 1
- Scheme
- MC-IEF
Lines connect the coordinator with its partners.
Results in brief
Doped Magnetic ZnO p-n Junction Heterostructures for Nano-Spintronic Devices
In the course of this project we carried out a detailed structural and functional characterisation of doped ZnO nanowires synthesised within polycabonate templates via a direct electrodeposition technique. The composition and structure of the nanowires were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), extended x-ray absorption fine structure (EXAFS) and x-ray absorption near edge structure (XANES). The magnetic properties of the systems were studied using a superconducting quantum interference device (SQUID) magnetometry. In the case of transition metal doped ZnO nanowires such Co-doped ZnO nanowires it was observed that although the nanowires are polycrystalline in nature they are highly textured and have both single crystal and polycrystalline regions. Using TEM and corresponding elemental detection methods it was also observed that there were no detectable variation in the composition between the different regions of the nanowire EXAFS and XANES measurements the absence of secondary phases such as ZnCo alloys or Co nanoclusters and proved that Co is fully incorporated into the lattice Magnetic measurements confirmed the presence of a magnetically ordered phase at T<350 K, which is attributed to dilute Co2+ ions in the ZnO nanowires. Co-doping with Ag+ or Cu+ to produce p-type material was achieved by simple bath modification; Ag-doping resulted in the formation of a black film due to the generation of colour centres in the material; this effect is still being investigated at the host institution. In this project have used a simple low-cost, low temperature electrodeposition process to synthesise doped ZnO nanowires with ordered architectures. A thorough characterisation of these 1-d nanostructured arrays has helped us develop a better fundamental understanding of the relationship between structure and functional properties of these materials which are potential candidates for use in future functional electronic devices.
Data: CORDIS, © European Union
Project objective
Semiconductor materials form the basis of modern electronics, communication, data storage and computing technologies. One of today’s major challenges for the development of future technologies is the realization of devices that control not only the electron charge, as in present electronics, but also its spin, setting the basis for future spintronics. Spintronics represents the concept of the synergetic and multifunctional use of charge and spin dynamics of electrons, aiming to go beyond the traditional dichotomy of semiconductor electronics and magnetic storage technology. The most direct method to induce spin-polarized electrons into a semiconductor is by introducing appropriate transition metal dopants producing a dilute magnetic semiconductor (DMS). The seamless integration of future spintronic architectures into nanodevices would require the fabrication 1-D DMS nanostructures in well defined architectures. In this project we propose to use a simple low-cost, low-temperature electrodeposition process to not only synthesise and characterise ZnO based bipolar DMS nanowire heterostructures but, even more importantly, fabricate an array of p-n and n-p-n junctions which could lead to novel nano-spintronic devices within ordered pre-defined nano-architectures. We will study the structural and functional properties of these heterostructures, which could have applications such as spin polarised LED and spin polarised bipolar junction transistor. By fully exploring the parameters controlling the growth and functionality of these materials we will try to gain a holistic understanding of the processing/structure/property relationships for this system. The ultimate goal of this project is to be able to design and fabricate specific nanowire heterostructures with tuneable magnetic and electrical properties which could lead to practical spintronic applications. Moreover this approach is inherently clean and scalable and easily integrated within current industrial practice.
Original text from CORDIS.
Participants
- IMPERIAL COLLEGE OF SCIENCE TECHNOLOGY AND MEDICINE · LondonCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union