A photoanode with hierarchical nanoforest TiO2 structure and silver plasmonic nanoparticles for flexible dye sensitized solar cell

Abstract

Due to unique photovoltaic properties, the nanostructured morphologies of TiO2 on flexible substrate have been studied extensively in the recent years for applications in dye sensitized solar cells (DSSCs). Microstructured electrode materials with high surface area can facilitate rapid charge transport and thus improve the light-to-current conversion efficiency. Herein we present an improved photoanode with forest like photoactive TiO2 hierarchical microstructure using a simple and facile hydrothermal route. To utilize the surface plasmon resonance (SPR) and hence increase the photon conversion efficiency, a plasmonic nanoparticle Ag has also been deposited using a very feasible photoreduction method. The branched structure of the photoanode increases the dye loading by filling the space between the nanowires, whereas Ag nanoparticles play the multiple roles of dye absorption and light scattering to increase the light-to-current conversion efficiency of the device. The branched structure provides a suitable matrix for the subsequent Ag deposition. They improve the charge collection efficiency by providing the preferential electron pathways. The high-density Ag nanoparticles deposited on the forest like structure also decrease the charge recombination and therefore improve the photovoltaic efficiency of the cells. As a result, the DSSC based on this novel photoanode shows remarkably higher photon conversion efficiency (ηmax = 4.0% and ηopt = 3.15%) compared to the device based on pristine nanowire or forest-like TiO2 structure. The flexibility of the device showed sustainable and efficient performance of the microcells.

Quantum Dot Sensitized Solar Cell: Photoanodes, Counter Electrodes, and Electrolytes

“…As reported by Tung et al, by doping Mn and Cu into CdSe QDs, the efficiencies of QDSSCs were increased from 2.55% with pure tandem-structure photoanode to 3.77% and 4.22% with Mn- and Cu-doped photoanode, respectively. These results have good agreement with those in Reference [ 97 ]. The current density enhancement in QDSSCs with the doped photoanode was due to the presence of doping metal energy level in the bandgap of pure QDs, as can be seen in Figure 7 b.…”

Au@Ag Dendritic Nanoforests for Surface-Enhanced Raman Scattering Sensing

“…The two-dimensional structure is also not easy to capture target molecules in microfluidics. Metal or dielectric DNFs structure [ 10 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] has complex three-dimensional cross-linking networks to fix many target molecules. Chan et al presented that the Ag dendrites formed and protected by a 2 nm SiO 2 film on a Si surface [ 17 ] demonstrated a high sensitivity of 10 −8 M R6G Raman response.…”

Photovoltaic Performance of Spherical TiO2 Nanoparticles Derived from Titanium Hydroxide Ti(OH)4: Role of Annealing Varying Temperature

“…The energy difference ( ∆Ev ∼ 2.15 eV) between the valence states of Si and TiO 2 were too large, preventing the holes extraction at Si-TiO 2 interface and thus acted as HBL [47]. In addition, work functions (Φ) of Ag (4.28 eV) and Al (4.26 eV) facilitated the rapid acceptance of the carriers towards the electrodes [6,48,49]. On top, the values of Ec, Ev, and Φ of the materials in the proposed solar cell were fluctuated, slightly depending on the method of thin films deposition [50].…”