Spin injection in n-type resonant tunneling diodes
1 Physics Department, Federal University of São Carlos, São Carlos 13.565-905, Brazil
2 Gleb Wataghin Physics Institute, UNICAMP, Campinas, 13083-970, Brazil
3 School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
4 Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield, S10 2TN, UK
Nanoscale Research Letters 2012, 7:592 doi:10.1186/1556-276X-7-592Published: 25 October 2012
We have studied the polarized resolved photoluminescence of n-type GaAs/AlAs/GaAlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. Under resonant tunneling conditions, we have observed two emission lines attributed to neutral (X) and negatively charged excitons (X−). We have observed a voltage-controlled circular polarization degree from the quantum well emission for both lines, with values up to −88% at 15 T at low voltages which are ascribed to an efficient spin injection from the 2D gases formed at the accumulation layers.