Integrated Nanostructured Systems

EL spectrum from a spin-LED that incorporates a single layer ofd InAs QDs at the center of the device. The red (black) line represents the EL analysed as σ+(σ-). The blue line denotes the circular polarization P versus emitted photon energy.

During the last few years Petrou's research has concentrated on the study of electrical spin injection from ferromagnetic metals into semiconductor heterostructures such as GaAs quantum wells (QWs) and InAs quantum dots (QDs). Optical methods to measure the degree of spin polarization of injected carriers have been explored. Optical pumping and the related Hanle and oblique Hanle effects have been used in the study of spintronic devices.

Spintronics; spectroscopy.

Use of 7 tesla optical magnet cryostat.

Efficient electrical spin injection from a magnetic metal/tunnel barrier contact into a semiconductor, A.T. Hanbicki, B.T. Jonker, Y.D. Park, G. Itskos, G. Kioseoglou, and A. Petrou, Appl. Phys. Lett. 80, 1240, (2002). http://link.aip.org/link/?APPLAB/80/1240/1

Reduction of spin injection efficiency by interface defect spin scattering in ZnMnSe/AlGaAs-GaAs spin polarized light emitting diodes, R.M. Stroud, A.T. Hanbicki, Y.D. Park, G. Kioseoglou, A.G. Petukhov, B.T. Jonker, G. Itskos, and A. Petrou, Phys. Rev. Lett.89, 166602-1, (2002). http://link.aps.org/doi/10.1103/PhysRevLett.89.166602

Analysis of the transport process providing spin injection through an Fe/AlGaAs Schottky barrier, A.T. Hanbicki, O.M.J. van't Erve, R. Magno, G. Kioseoglou, C.H. Li, B.T. Jonker, G. Itskos, R. Mallory, M. Yasar, and A. Petrou, Appl. Phys. Lett. 82, 4092, (2003). http://link.aip.org/link/?APPLAB/82/4092/1

A comparison of Fe/Schottky and Fe/Al2O3 tunnel barrier contacts for electrical spin injection into GaAs, O.M.J. van't Erve, G.Kioseoglou, A.T. Hanbicki, C.H. Li, B.T. Jonker, R. Mallory,M. Yasar, and A. Petrou, Appl. Phys. Lett. 84, 4334 (2004). http://link.aip.org/link/?APPLAB/84/4334/1

Spin injection across (110) interfaces: Fe/GaAs(110) spin LEDs, C.H. Li, G. Kioseoglou, O.M.J. van't Erve, A. T. Hanbicki, B.T. Jonker, R. Mallory, M. Yasar, and A. Petrou, Appl.Phys.Lett. 85, 1544, (2004). http://link.aip.org/link/?APPLAB/85/1544/1

Electrical spin pumping of quantum dots at room temperature, C.H. Li, G. Kioseoglou, O. M .J. van't Erve, M.E. Ware, D. Gammon, R.M. Stroud, B.T. Jonker, R. Mallory, M. Yasar, and A. Petrou, Appl. Phys. Lett. 86, 132503, (2005). http://link.aip.org/link/?APPLAB/86/132503/1

Bias-controlled hole degeneracy and implications for quantifying spin injection, G. Kioseoglou, A.T. Hanbicki, B.T. Jonker, and A. Petrou, Appl. Phys. Lett., 87, 122503, (2005). Also appeared in the September 26, 2005 issue of the Virtual Journal of Nanoscale Science and Technology. http://link.aip.org/link/?APPLAB/87/122503/1

Phonon assisted recombination in Fe based spin LEDs, R. Mallory, M. Yasar, G. Itskos, A. Petrou, G. Kioseoglou, A.T. Hanbicki, C.H. Li, O.M.J. van't Erve, B.T. Jonker, M. Shen, and S. Saikin, Phys. Rev. B 73 , 115308 (2006). Also appeared in the March 20, 2006 issue of the Virtual Journal of Nanoscale Science and Technology. http://link.aps.org/abstract/PRB/v73/e115308

Electrical spin injection into the InAs/GaAs wetting layer, C.H. Li, G. Kioseioglou, A.T. Hanbicki, R. Goswami, G. Spanos, C.S. Hellberg, B.T. Jonker, M. Yasar, and A. Petrou, Appl. Phys. Lett., 91, 262504, (2007). http://link.aip.org/link/?APPLAB/91/262504/1