Highly soluble energy relay dyes for dye-sensitized solar cells

High solubility is a requirement for energy relay dyes (ERDs) to absorb a large portion of incident light and significantly improve the efficiency of dye-sensitized solar cells (DSSCs). Two benzonitrile-soluble ERDs, BL302 and BL315, were synthesized, characterized, and resulted in a 65% increase in the efficiency of TT1-sensitized DSSCs. The high solubility (180 mM) of these ERDs allows for absorption of over 95% of incident light at their peak wavelength. The overall power conversion efficiency of DSSCs with BL302 and BL315 was found to be limited by their energy transfer efficiency of approximately 70%. Losses due to large pore size, dynamic collisional quenching of the ERD, energy transfer to desorbed sensitizing dyes and static quenching by complex formation were investigated and it was found that a majority of the losses are caused by the formation of statically quenched ERDs in solution

Oxide‐Based Solid‐State Batteries: A Perspective on Composite Cathode Architecture

The garnet-type phase Li$_7$La$_3$Zr$_2$O$_{12}$ (LLZO) attracts significant attention as an oxide solid electrolyte to enable safe and robust solid-state batteries (SSBs) with potentially high energy density. However, while significant progress has been made in demonstrating compatibility with Li metal, integrating LLZO into composite cathodes remains a challenge. The current perspective focuses on the critical issues that need to be addressed to achieve the ultimate goal of an all-solid-state LLZO-based battery that delivers safety, durability, and pack-level performance characteristics that are unobtainable with state-of-the-art Li-ion batteries. This perspective complements existing reviews of solid/solid interfaces with more emphasis on understanding numerous homo- and heteroionic interfaces in a pure oxide-based SSB and the various phenomena that accompany the evolution of the chemical, electrochemical, structural, morphological, and mechanical properties of those interfaces during processing and operation. Finally, the insights gained from a comprehensive literature survey of LLZO–cathode interfaces are used to guide efforts for the development of LLZO-based SSBs

Dual absorber Fe₂O₃/WO₃ host-guest architectures for improved charge generation and transfer in photoelectrochemical applications

In this study the influence of the spatial distribution and of different nanostructures of WO3 and Fe2O3 in the dual absorber system Fe2O3/WO3 was systematically investigated for the first time. WO3 was applied as a scaffold and/or as a surface treatment to mesoporous Fe2O3 films. Both approaches strongly increased the performance compared to the individual photoabsorbers. By combining a host guest architecture with a surface treatment, current densities of about 0.7 mA cm(-2) at 1.23 V versus reversible hydrogen electrode under AM 1.5 illumination with an incident photon-to-current efficiency of 17% at 350 nm were achieved without the use of further catalysts. We could identify several beneficial interactions between Fe2O3 and WO3. WO3 strongly scatters visible light, resulting in increased absorption by Fe2O3 and higher current densities. We also determined a cathodic shift in the onset potential to 0.8 V and increased transfer rates of up to 88%. This combination of beneficial effects proves the viability of the presented device architecture