(546b) Ordered Nanoarchitectures Improve Plasmon Enhancement near Semiconductor Bandgaps in the near-IR

Plasmon-enhancement of photovoltaics (PV) increases optical transition rate due to near-field plasmon absorption, and photocurrent generation from light trapping due to scattering. But enhancement is limited to plasmon resonant wavelengths. And increased thermalization and recombination, costly top-down fabrication, complex modeling, and distant semiconductor bandgaps prevent plasmons from sufficiently reducing PV cost per watt. We present a novel, bottom-up, lithographic method to fabricate ordered nanoarchitectures (see [figure 1]) to specifications set by a new exact solution to Maxwell's equations for electromagnetic interaction in these systems. These architectures scatter light at grazing angles, which maximizes light trapping. Lower particle densities reduce thermalization and recombination. In ordered nanoarchitectures, plasmons can couple with synchronous far-field radiation (SRPE) at infrared wavelengths near semiconductor bandgaps, producing >10-fold increases in local absorption and scattering that appear experimentally. Figure 2 [figure 2] shows spectra for single or random NP (green) vs. NP square lattice (blue) for Au and Si (inset). Au lattice SRPE peak is >102-fold higher than Si lattice SR peak, which lacks LSP, and >10-fold higher than Au NP LSP peak. The model identifies specifications to maximize semiconductor enhancement.