The project addresses novel contact concepts for the injection of spin-polarized electrons into semiconductors. Spin transport in semiconductors will be the basis for new spintronic devices that will give raise to a new class of semiconductor elements with enhanced functionality and low power consumption. This topic is addressed in two ways. Tunnelling contacts and barriers for hot electron injection will be fabricated using transition metal Ferro magnets that are currently available and are ferromagnetic at room temperature. As an alternativearized magnetite contacts will be fabricated and optimised on semiconductor structures. Using optical and electrical characterization of light emitting diodes and lateral transport devices. The final goal of the project is the realization of spin injection at room temperature and the assessment of the technology and the boundary conditions for future industrial applications.
The main objective is the development of contacts for spin injection into semiconductors, aiming at novel spintronic semiconductor applications:
1) Investigate new contact concepts for spin injection intop semiconductors using ferromagnetic metals. The contacts will be based on tunnel barriers and hot electron transport and will be operating at room temperature;
2) Investigate contacts for room temperature spin injection into semiconductors based on highly spin-polarized manganites;
3) Establish the boundary conditions for the operation and fabrication of devices based on spin injection;
4) Assess the developed technology and provide the boundary conditions for industrial applications.
DESCRIPTION OF WORK
Room temperature spin injection into semiconductors will be attempted by developing new contact concepts. Ferro magnet/insulator/semiconductor tunnelling contacts as well as vacuum metal bonded hot electron transistor structures will be used to inject spin polarized electrons into III/V-semiconductors and silicon. The performance will be investigated by electrical transport experiments and optical experiments. Especially highly time resolved optical measurements will be used to investigate the spin relaxation of hot electrons injected into a semiconductor. Highly spin polarized magnetite contacts will be deposited and optimised on various semiconductors. These contacts will be used as direct contacts and in a tunnelling geometry in order to assess their suitability for spin injection into semiconductors. All contacts will be optimised for high injection efficiency. The micro magnetic properties of the contacts will be investigated using spin polarized STM and other techniques. Based on the results a three terminal device with implemented GMR functionality will be fabricated. The boundary conditions for industrial application of the results will be established.
Funding SchemeCSC - Cost-sharing contracts
OX1 2JD Oxford
7522 NB Enschede