Spin Dependent Recombination and Variable Range Hopping in the Absence of an Oscillating Magnetic Field in Inorganic Materials and Devices*

We have investigated changes in current dominated by spin dependent recombination and spin dependent variable range hopping [1-3] in a variety of systems resulting from the application of relatively small magnetic fields. We compare the current changes resulting from the small magnetic fields to current changes induced by electrically detected magnetic resonance. Magnetic fields of order one mT can yield significant current changes in silicon and silicon carbide based metal oxide semiconductor (MOS) field effect transistors (MOSFETs), bipolar junction diodes and transistors, pin diodes, MOS gated diodes, amorphous silicon nitride, amorphous silicon dioxide and amorphous carbon thin films. These near zero magnetic field induced changes are easily observable at room temperature. The near zero magnetic field response is invariably a strong function of bias applied to the device structures; both the overall amplitude of the response and the “shape” of the response can be strongly influenced by the biasing conditions. In some cases one may also apply a time dependent biasing waveform to explore the kinetics of charge capture events. In this presentation I will discuss the potentially rich source of information about electronic transport which these electron spin based measurements can provide.
(Work done in collaboration with M. Flatte, U of Iowa, N. Harmon, U of Evansville, C.J. Cochrane, JPL/Cal Tech and others.)
1. J.P. Ashton et al. IEEE Trans NS. vol. 66,428 (2019)
2. M.A. Anders et al. J. Appl. Phys. vol. 122234503 (2017)
3.M.J. Mutch et al. Appl. Phys Lett. vol. 109062403 (2016)