Quantitative chemical analysis of perovskite deposition using spin coating

Lead and halide ion compositions of spin coated organo-lead halide perovskite films have been quantified using ion chromatography (IC) and atomic absorption spectroscopy (AAS) using perovskite films manufactured by 5 different researchers (3 replicates per treatment) to monitor variability between researchers and individual researcher reproducibility. Planar and mesoporous TiO2-coated glass substrates have been studied along with tribromide (CH3NH3PbBr3), triiodide (CH3NH3PbI3) and mixed halide (CH3NH3PbI3�xClx) perovskite films. The data show low yields of spin coated perovskite material (ca. 1%) and preferential deposition of I� over Cl� in mixed halide films

Rapid, 5 min, low temperature aqueous platinization for plastic substrates for dye-sensitized solar cells

This paper reports a rapid (5 min), low temperature (120 �C) method to platinize the counter electrodes of dye-sensitized solar cell (DSC) devices. This new method uses aqueous solutions and is based on chemical bath deposition of an activating Pd layer followed by Pt only using H2 gas as the reductant. This method has been tested on flexible, plastic substrates (indium tin oxide-coated polyethylene terephthalate or polyethylene naphthalate, ITO-PET or ITO-PEN, respectively). We report device efficiencies up to 7.2% on ITO-PET which is comparable to devices made using high temperature (400 �C) processing on rigid, fluoride-doped tin oxide (FTO) glass counter electrodes. The method is scalable and suitable for continuous roll-to-roll production

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)

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

Novel benzothiazole half-squaraines: model chromophores to study dye–TiO2 interactions in dye-sensitized solar cells

We report the synthesis of 9 new half squaraine (HfSQ) dyes; 5 containing a benzothiazole moiety and 4 containing an indolenine moiety. X-ray single crystal structural and characterisation data have been correlated with device data to understand the widely reported but poorly understood influence of S heteroatoms on DSC device performance. The S heteroatom in these new dyes has also been used as an atomic probe of the dye–TiO2 interface to dye binding and orientation. Thus, for the first time, using the S heteroatom probe, angle-resolved X-ray photoelectron (AR-XPS) data have shown these dyes sit horizontally at the dye–TiO2 interface confirmed by DFT computer modelling of novel and analogous HfSQ dyes with a benzoindole backbone