Fusing the Bulk and the Nanoscale with Light: Surprises and Opportunities

J. Spanier
Drexel University,
United States

Keywords: nanoelectronic devices, nanoscale


Electronic properties of solids lie at the interface of the physical sciences and engineering and are rooted in structure, where free electrons in nanoscale media drive information and energy technologies. Our tendency to categorize materials according to electronic conduction implies well-defined boundaries in this classification, informing materials design and selection. Despite many decades of advances in knowledge of how structure influences electronic properties, prevailing models that describe photoconductivity focus on inter-band transitions or photo-ionization of defect-bound carriers. Conventional optoelectronic properties are thus generally limited to light-induced generation of ordinary conduction band electrons that, if carrying excess energy (i.e., are hot), rapidly cool before diffusing or drifting. One optoelectronic interaction is remarkably different: the interaction of light with crystals lacking a center of symmetry produces hot electrons that, unlike in ordinary photoconduction, can travel remarkably far in an electrical insulator without scattering. I will provide a brief overview of this intriguing so-called bulk photovoltaic effect. Pursuing and embracing the seemingly contradictory aspects of nanoscale phenomena and features with this inherently bulk phenomenon has the potential to leverage nanotechnology to advance a new frontier in optoelectronics and energy conversion