A novel observation of controlled carrier hopping process in B-doped Si NCs/SiC multilayers at low temperatures

Recent advances in quantum computing devices make studies on the carrier transport behaviors of silicon nanocrystals under cryogenic temperature a most important subject. In this work, we study the electrical properties modified by B dopants in silicon nanocrystals/SiC multilayers. Mobility measurement shows the scattering mechanism that dominates in our samples in low temperature range is ionized impurity scattering. Three carrier transport behaviors are identified as variable range hopping (20-100 K), multiple phonon hopping (100-500 K) and thermally activated mechanisms (500-660 K). At temperature ranges as low as 30 K, we observe the effect of Coulomb gap in B-doped Si NCs/SiC multilayers that obey the Efros and Shklovskii law, which was not present in our previous studies concerning silicon nanocrystals multilayers. The crossover temperature TC is observed to increase with rising B-doping concentrations, which demonstrates another interesting effect of doping in controlling the electrical properties of silicon nanocrystals.