Sulfur hyperdoping by fs laser irradiation is a promising process for improving absorption properties of crystalline silicon which indicates its suitability for manufacturing intermediate band silicon solar cells. Here, first results of a novel approach to study the electrical and structural properties of sulfur hyperdoped regions of p-type silicon substrates are presented. In addition to electron beam induced current (EBIC) and transmission electron microscopy (TEM) in cross-section geometry, shallow-angle bevel polishing is used to employ surface sensitive techniques, such as atomic force microscopy (AFM) and Kelvin force microscopy (KFM). The latter reveals high lateral electric fields in regions beneath the crests of the surface topography, while EBIC shows an enhanced recombination activity at the location of the voltage drops. Both these effects are related to extended defects revealed by TEM and a possible lateral variation of sulfur concentrations. AFM image (top) and KFM map (bottom) showing a voltage drop on the surface of a terrace produced by bevel polishing of sulfur hyperdoped silicon.

Delocalized carbon-based radical species with unpaired spin, such as the phenalenyl (PLY) radical, have opened avenues for developing multifunctional organic spintronic devices. Using direct laser writing and in situ deposition, we successfully fabricated Cu-PLY-and Zn-PLY-based organic magnetic tunnel junctions (OMTJs) with improved morphology and a reduced junction area of 3 × 8 μm 2 . The nonlinear and weakly temperature-dependent current−voltage (I−V) characteristics in combination with the low organic barrier height suggest tunneling as the dominant transport mechanism in the structurally and dimensionally optimized OMTJs. Cu-PLY-based OMTJs show significant magnetoresistance up to 14% at room temperature due to the formation of hybrid states at the metal−molecule interfaces called "spinterface", which reveals the importance of spin-dependent interfacial modification in OMTJs' design. Additionally, at high bias, in the absence of a magnetic field, OMTJ shows stable voltage-driven resistive switching. Cu-PLY having spin 1/2 with net magnetic moment demonstrates magnetic hardening between the surface molecule at the Co interface and gives rise to stable MR, which suggests its use as a feasible and scalable platform for building molecular-scale quantum memristors and processors.