Probing metastable space-charge potentials in a wide bandgap semiconductor

Despite a long history of study of space charge potentials, present models are largely based on the notion of steady state equilibrium, ill-suited to describe wide-bandgap semiconductors with moderate to low concentrations of defects. In this work we build on color centers in diamond to locally inject carriers into the crystal and probe their evolution as they propagate in the presence of external and internal electric potentials¹. We observe the formation of metastable charge patterns whose shape and concomitant field can be engineered through the timing of carrier injection and applied voltages. With the help of previously crafted charge patterns, we unveil a rich interplay between local and extended sources of space charge field, which we then exploit to show space-charge-induced carrier guiding.
1. A. Lozovoi et al. Probing metastable space-charge potentials in a wide bandgap semiconductor (2020) Physical Review Letters (in press)