Porphyrin dye-sensitised solar cells utilising a solid-state electrolyte Vanessa Armel,* Jennifer M. Pringle, Pawel Wagner, Maria Forsyth, David Officer and Douglas R. MacFarlane Materials and methods Succinonitrile (99 %) lithium iodide (99.9 %) and iodine (99.99 %) were purchased from Sigma Aldrich and used as received. [C 4 mpyr][I] was synthesised according to literature procedures and recrystallised several times from acetonitrile/ethylactetate. 1 SiO 2 (7nm) was purchased from Degussa. All chemicals were stored in a nitrogen glove box and the electrolytes were also prepared inside the glove box. Thermal analysis Differential Scanning Calorimetry (DSC) characterization was performed on a heat flux type DSC. A T.A Instruments Q100 differential scanning calorimeter was used. Scans were carried out at a heating/cooling rate of 10°C /min in the range of -140 °C to 150 °C or -100 °C to 80 °C. Thermal scans below room temperature were calibrated with the cyclohexane solid-solid transition and melting point at -87.0 °C and 6.5 °C respectively. Thermal scans above room temperature were calibrated with the indium, tin and zinc with the melting points of 156.6 °C, 231.9 °C and 419.5°C respectively. All DSC analysis was performed using an aluminum pan with a sample weight of approximately 5 mg. Moisture sensitive and hygroscopic compounds were loaded in a nitrogen glove box. Entropies are normalised for succinonitrile content. AC conductivity measurement The ionic conductivity of all samples was evaluated using a.c. impedance spectroscopy. The measurements were performed with a frequency response analyzer (FRA, Solartron 1296), driven by Solartron impedance measurements software version 3.2.0. The temperature was controlled using a Eurotherm Model 2204 temperature controller). The data typically presented as a single semicircle from which the conductance of the samples was determined using the real axis intercept in the Nyquist plot of the impedance data. A locally designed dip cell was used and the cell constant was determined using 0.01M KCl. Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2011