4 research outputs found
A novel dimethylformamide (DMF) free bar-cast method to deposit organolead perovskite thin films with improved stability
We report a solvent-free approach to synthesizing organolead
perovskites by using solid state reactions to coat perovskite crystals
onto Al2O3 or TiO2 nanoparticles followed by addition of terpineol
affording perovskite inks. We have bar cast these inks to produce
photoactive perovskite thin films which are significantly more
stable to humidity than solution-processed films. This new method
also avoids the use of toxic DMF solvent
A perspective on using experiment and theory to identify design principles in dye-sensitized solar cells
Dye-sensitized solar cells (DSCs) have been the subject of wide-ranging studies for many
years because of their potential for large-scale manufacturing using roll-to-roll processing
allied to their use of earth abundant raw materials. Two main challenges exist for DSC
devices to achieve this goal; uplifting device efficiency from the 12 to 14% currently
achieved for laboratory-scale ‘hero’ cells and replacement of the widely-used liquid
electrolytes which can limit device lifetimes. To increase device efficiency requires optimized
dye injection and regeneration, most likely from multiple dyes while replacement
of liquid electrolytes requires solid charge transporters (most likely hole transport materials
– HTMs). While theoretical and experimental work have both been widely applied to
different aspects of DSC research, these approaches are most effective when working in
tandem. In this context, this perspective paper considers the key parameters which
influence electron transfer processes in DSC devices using one or more dye molecules
and how modelling and experimental approaches can work together to optimize electron
injection and dye regeneration.
This paper provides a perspective that theory and experiment are best used in tandem to study
DSC device
Surface interactions of half-squaraine dyes in dye-sensitized solar cells
This paper presents a summary of our recent work on half-squaraine dyes for use as sensitizers in dye-sensitized solar cells. Our data include a review of the highest efficiency half-squaraine dyes to date. The discussion also considers how Jsc varies with functionalization of the Hf-SQ dyes and how these modifications affect device lifetime. The paper also discusses recent papers which consider the influences of the position and number of carboxylate linker groups on the chromophore
Double Linker Triphenylamine Dyes for Dye-Sensitized Solar Cells
Most organic dyes synthesized for dye-sensitized solar cells (DSC) use a single linker group to bind to the metal oxide photo-anode. Here we describe the synthesis and testing of two new triphenylamine dyes containing either two carboxylic acids 5-[2-(4-diphenylamino-phenyl)-vinyl]-isophthalic acid (10) or two cyanoacrylic acids (2Z, 2′Z)-3, 3′-(5-((E)-4-(diphenylamino) styryl)-1, 3-phenylene) bis (2-cyanoacrylic acid) (8) as linker groups. Full characterization data are reported for these dyes and their synthetic intermediates. DSC devices have been prepared from these new dyes either by passive or fast dyeing and the dyes have also been tested in co-sensitized DSC devices leading to a PCE (η = 5.4%) for the double cyanoacrylate linker dye (8) co-sensitized with D149. The dye:TiO2 surface interactions and dye excitations are interpreted using three modelling methods: density functional theory (at 0 K); molecular dynamics (at 298 K); time dependent density functional theory. The modelling results show the preferred orientation of both dyes on an anatase (1 0 1) TiO2 surface to be horizontal, and both the simulated and experimental absorption spectra of the dye molecules indicate a red shifted band for (8) compared to (10). This is in line with broader light harvesting and Jsc for (8) compared to (10)