Surface plasmons for improving the performance of quantum dot structures for third generation solar cell applications

We use room temperature photoluminescence (PL) measurements to investigate the effect of surface plasmons on the emission from a single layer quantum dot structure. Silver metal nanoparticles are fabricated using self assembly techniques and tailored to provide selective scattering by varying the size of the particles. We report an 8 fold increase in the PL intensity at the peak emission wavelength of the silicon nanocrystals and up to a 15 fold increase in the emission corresponding to the surface plasmon resonance frequency. We attribute this enhnacement to both the scattering in and outcoupling of light by excitation of surface plasmons. The energy transfer from the nanocrystal excitons to surface plasmons and vice versa is tunable and has the potential to increase absorption in the bandgap engineered quantum dot cells for third generation photovoltaic (PV) applications such as tandem solar cells and hot-carrier cells.