We report electroabsorption measurements of polymer light-emitting diodes, (LEDs), fabricated with poly(4-4′-diphenylene diphenylvinylene), PDPV, as the emissive layer, Ca–Al cathodes, and indium tin oxide (ITO) anodes, with and without a doped conducting polymer hole injection/transport layer, namely poly(3,4-ethylene dioxythiophene), PEDOT, doped with poly(styrene sulfonate), PSS−. In these structures, the bias at which the electroabsorption signal is null corresponds to the difference between the electrodes’ work functions. We find that such a built-in voltage increases by 0.5 V when a PEDOT:PSS film is incorporated between the ITO electrode and the emissive layer. This leads to a marked reduction of the anode barrier height at the hole-injecting interface, and accounts for a variety of improvements brought about by the PEDOT insertion, namely: (a) the increase of luminescence efficiency, (b) the reduction of the turn-on voltage, and (c) the increase of the device lifetime.

An overview of the state of the art dye solar module technology and innovations required for further development is presented.

Perovskite solar cells have attracted enormous interest since their discovery only a few years ago because they are able to combine the benefits of high efficiency and remarkable ease of processing over large areas. Whereas most of research has been carried out on glass, perovskite deposition and synthesis is carried out at low temperatures (<150 °C) to convert precursors into its final semiconducting form. Thus, developing the technology on flexible substrates can be considered a suitable and exciting arena both from the manufacturing view point (e.g. web processing, low embodied energy manufacturing) and that of the applications (e.g. flexible, lightweight, portable, easy to integrate over both small, large and curved surfaces). Research has been accelerating on flexible PSCs and has achieved notable milestones including PCEs of 15.6% on laboratory cells, the first modules being manufactured, ultralight cells with record power per gram ratios, and even cells made on fibres. Reviewing the literature, it becomes apparent that more work can be carried out in closing the efficiency gap with glass based counterparts especially at the large-area module level and, in particular, investigating and improving the lifetime of these devices which are built on inherently permeable plastic films. Here we review and provide a perspective on the issues pertaining progress in materials, processes, devices, industrialization and costs of flexible perovskite solar cells.