Jointly Tuned Plasmonic–Excitonic Photovoltaics Using Nanoshells

Abstract

Recent advances in spectrally tuned, solution-processed plasmonic nanoparticles have provided unprecedented control over light's propagation and absorption via engineering at the nanoscale. Simultaneous parallel progress in colloidal quantum dot photovoltaics offers the potential for low-cost, large-area solar power; however, these devices suffer from poor quantum efficiency in the more weakly absorbed infrared portion of the sun's spectrum. Here, we report a plasmonic-excitonic solar cell that combines two classes of solution-processed infrared materials that we tune jointly. We show through experiment and theory that a plasmonic-excitonic design using gold nanoshells with optimized single particle scattering-to-absorption cross-section ratios leads to a strong enhancement in near-field absorption and a resultant 35% enhancement in photocurrent in the performance-limiting near-infrared spectral region.

Recent advancements in plasmon-enhanced promising third-generation solar cells

“…In planar configuration, the maximum photocurrent enhancement obtained when metal NPs were incorporated at the distance of 220-260 nm from the illuminated side of QD film [110]. Figure 21A shows the absorption spectra of 400-nm-thick PbS CQD film with metal NPs at different locations [111]. As mentioned above, metal NPs were embedded in CQD solar cells by spin coating metal NP containing solution.…”

“…Interestingly, when metal NPs were close to ZnO nanowire, both V oc and FF values of these devices were significantly lower than those without metal NPs because the metal NPs in contact with the electron acceptor acted as a leakage path (back electron transfer), which lowered the Fermi level of the electron acceptor and the parallel resistance of solar cells as well. Three-dimensional FDTD simulations show that the best location for the inclusion of metal NPs is 260 nm away from the illuminated side of colloidal QD (CQD) film [111]. In planar configuration, the maximum photocurrent enhancement obtained when metal NPs were incorporated at the distance of 220-260 nm from the illuminated side of QD film [110].…”

“…As mentioned above, metal NPs were embedded in CQD solar cells by spin coating metal NP containing solution. For both configurations, the optimum concentration of the metal NPs in spin coating solutions was found to be 20-30 mg mL -1 [110,111]. Paz-Soldan et al theoretically evaluated the impact of differently shaped Au NPs in planar CQD solar cells using FDTD [111].…”

“…For both configurations, the optimum concentration of the metal NPs in spin coating solutions was found to be 20-30 mg mL -1 [110,111]. Paz-Soldan et al theoretically evaluated the impact of differently shaped Au NPs in planar CQD solar cells using FDTD [111]. They found that spherical dielectric metal oxide core@metal shell NPs (named as nanoshells) were more appropriate for the CQD solar cell application compared with spherical NPs and NRs because the scattering-to-absorption ratio of the former was significantly higher than the latter nanostructures ( Figure 21B and C).…”

Molecular interfaces for plasmonic hot electron photovoltaics

“…3 In particular, the use of metallic nanostructures has proved beneficial in a number of systems, from photovoltaics [4][5][6] to photodetectors. 2,7,8 The enhanced performance in these devices typically stems from the superior light trapping characteristics of such structures, which yield increased absorption in the surrounding semiconductors.…”