Rapid synthesis of ultralong silver nanowires (AgNWs) has been obtained using a one-pot polyol-mediated synthetic procedure. The AgNWs have been prepared from the base materials in less than one hour with nanowire lengths reaching 195 μ m, which represents the quickest synthesis and one of the highest reported aspect ratios to date. These results have been achieved through a joint analysis of all reaction parameters, which represents a clear progress beyond the state of the art. Dispersions of the AgNWs have been used to prepare thin, flexible, transparent and conducting films using spray coating. Due to the higher aspect ratio, an improved electrical percolation network is observed. This allows a low sheet resistance ( R _S = 20.2 Ω /sq), whilst maintaining high optical film transparency ( T = 94.7%), driving to the highest reported figure-of-merit (FoM = 338). Owing to the light-scattering influence of the AgNWs, the density of the AgNW network can also be varied to enable controllability of the optical haze through the sample. Based on the identification of the optimal haze value, organic photovoltaics (OPVs) have been fabricated using the AgNWs as the transparent electrode and have been benchmarked against indium tin oxide (ITO) electrodes. Overall, the performance of OPVs made using AgNWs sees a small decrease in power conversion efficiency (PCE), primarily due to a fall in open-circuit voltage (50 mV). This work indicates that AgNWs can provide a low cost, rapid and roll-to-roll compatible alternative to ITO in OPVs, with only a small compromise in PCE needed.

The proof of concept of using luminescent down shifting (LDS) layers as alternative UV filters for P3HT:PCBM OPVs is demonstrated using a lanthanide-based metal complex. The results are verified using a combination of indoor light soaking, with single cell devices, and outdoor performance monitoring, using a 16-cell monolithically connected OPV module. By applying the LDS layer, a ~5% relative enhancement in photocurrent is observed for both sets of devices. More significantly, indoor light soaking tests on single cell devices without encapsulation showed an 850% enhancement in the measured half-life (T50%). The OPV modules were encapsulated and tested for outdoor stability over a 70 day period in the Negev desert, Israel. The modules made with the LDS filter are shown to match the stability of those made with a commercial UV filter and outperform the modules with no filter applied, with a 51% enhancement in the measured stability (T75%). Significantly, the work provides clear experimental evidence that the LDS layer can act as a UV filter in OPVs without compromising the efficiency of the solar cell, thus providing an added benefit over commercial UV filters

The outdoor dependence of temperature and diurnal irradiance on inverted organic photovoltaic (OPV) module performance has been analysed and benchmarked against monocrystalline-silicon (c-Si) photovoltaic technology. This is first such report and it is observed that OPVs exhibit poorer performance under low light conditions, such as overcast days, as a result of inflexion behaviour in the current-voltage curves, which limits the open-circuit voltage (V_OC) and fill factor. These characteristics can be removed by photo-annealing at higher irradiance levels, which occur diurnally as irradiance increases after sunrise. We also report the first temperature coefficients for OPVs from outdoor data; the OPV modules showed a positive temperature coefficient, which compared to a negative coefficient from the c-Si modules. Overall, the cell degradation outdoors appears very severe for these modules and highlights the need for improved barrier.

The lamination of OPV modules to corrugated roof cladding has been undertaken.