Efficient Performance of Electrostatic Spray-Deposited TiO2 Blocking Layers in Dye-Sensitized Solar Cells after Swift Heavy Ion Beam Irradiation

Abstract

A compact TiO2 layer (~1.1 μm) prepared by electrostatic spray deposition (ESD) and swift heavy ion beam (SHI) irradiation using oxygen ions onto a fluorinated tin oxide (FTO) conducting substrate showed enhancement of photovoltaic performance in dye-sensitized solar cells (DSSCs). The short circuit current density (Jsc = 12.2 mA cm-2) of DSSCs was found to increase significantly when an ESD technique was applied for fabrication of the TiO2 blocking layer, compared to a conventional spin-coated layer (Jsc = 8.9 mA cm-2). When SHI irradiation of oxygen ions of fluence 1 × 1013 ions/cm2 was carried out on the ESD TiO2, it was found that the energy conversion efficiency improved mainly due to the increase in open circuit voltage of DSSCs. This increased energy conversion efficiency seems to be associated with improved electronic energy transfer by increasing the densification of the blocking layer and improving the adhesion between the blocking layer and the FTO substrate. The adhesion results from instantaneous local melting of the TiO2 particles. An increase in the electron transport from the blocking layer may also retard the electron recombination process due to the oxidized species present in the electrolyte. These findings from novel treatments using ESD and SHI irradiation techniques may provide a new tool to improve the photovoltaic performance of DSSCs.

N-Ion-implanted TiO2 photoanodes in quantum dot-sensitized solar cells

“…The nanoclump formation, which depends on electrostatic spray conditions, may be explained due to the lower columbic force resulting from weak repulsion among adjacent droplets compared to the stretching force. 31 Recent observations by Hwang et al on electrostatic spray-deposited TiO 2 showed similar hierarchical TiO 2 clumps. 32 These authors claimed that the clumps or cluster-like spheres were formed by the ultrafast evaporation of a high vapour pressure solvent at the surface, generating high convection forces and consequently forming tight clusters.…”

Tailored Synthesis of Porous TiO2 Nanocubes and Nanoparallelepipeds with Exposed {111} Facets and Mesoscopic Void Space: A Superior Candidate for Efficient Dye-Sensitized Solar Cells

“…These results suggest a rapid charge injection and transportation of photoexcited electrons in these bilayered architecture photoanode DSSCs. The main function of this under layer is to provide a compact layer/blocking layer for improving charge transport efficiency of the device reported frequently in many reports. , The bilayered DSSCs, SLP/TNF {111} -1 and SLP/TN {101} show power conversion efficiency of 9.15% and 7.59% respectively, due to improved J sc and V oc in these devices compared to single-layer DSSCs (TNF {111} -1 and TN {101} ).…”

“…The main function of this under layer is to provide a compact layer/blocking layer for improving charge transport efficiency of the device reported frequently in many reports. 52,53 The bilayered DSSCs, SLP/TNF {111} -1 and SLP/TN {101} show power conversion efficiency of 9.15% and 7.59% respectively, due to improved J sc and V oc in these devices compared to single-layer DSSCs (TNF {111} -1 and TN {101} ). Electrochemical impedance spectroscopy (EIS) measurements were conducted on symmetrical cells, and the results are plotted in the form of Nyquist plots (Figure 9).…”

Impact of Conformality and Crystallinity for Ultrathin 4 nm Compact TiO2 Layers in Perovskite Solar Cells

“…The deposition methods for the com‐TiO 2 layer in PSCs are adapted from DSSCs and quantum‐dot‐sensitized solar cells (QDSSCs) but should be reoptimized for PSCs . For both architectures, the layer is primarily deposited by aerosol spray‐pyrolysis, though other methods are also used, for example spin coating, electrostatic spray deposition, chemical vapor deposition, thermal oxidation, electrochemical techniques, electrodeposition, and atomic layer deposition (ALD) . In PSCs, the impact of com‐TiO 2 film thickness has been studied to optimize device fabrication, often along with the comparison of different deposition techniques, showing that both thickness and deposition method can impact efficiency.…”