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The current-position response in a-Si:H thin film position sensitive detector is analysed in terms of its equivalent circuit and the potential gradient in the transparent conductive oxide (TCO) layer. The TCO resistance and load resistance effect on the current response are analysed and compared with the experimental results. The current-position response depends on the ratio R load / R TCO instead of on the individual values.

International audience; Inorganic/organic (hybrid) complementary electrochromic devices (ECDs) of the type [transparent conducting oxide (TCO)//inorganic counter electrode/hydrophobic electrolytic membrane/polymeric working electrode//TCO] were assembled. The working electrodes consisted of spin-coated polymer films prepared by moderator-controlled in situ oxidative chemical polymerisation of 3{,}4-ethylene dioxythiophene (EDOT). Thin{,} galvanostatically deposited Prussian Blue (PB) films were employed as counter electrodes. Besides F : SnO2 (FTO)/glass and Sn : In2O3 (ITO)/glass{,} a flexible ITO/PET film was alternatively used for materials deposition. In order to attain the maximum device performance{,} the PB charge capacity was monitored and adapted to the capacity of the EDOT polymer films. The two electrochromic electrodes were separated by a novel hydrophobic polymer electrolyte based on a gel of 1-butyl-3-methyl-imidazolium bis (trifluoromethanesulfonyl)imide (BMI-TFSI) and poly(methylmethacrylate) (PMMA){,} with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as the salt. The influence of two parameters—ITO sheet resistance and the PMMA content in the electrolyte—on the final device properties was investigated. The ITO sheet resistance value proved to be crucial for the switching kinetics. The variation of the weight ratio of PMMA in the electrolyte showed that the effect on the kinetics is small whereas the change in absorbance is highly affected. The properties of the complementary glass-based devices were eventually compared to the corresponding plastic-based electrochromic elements. First attempts to scale up the technology were made for flexible 12 × 15 cm2 (active area) devices.

A grid-connected PV system is made up of an array of panels mounted on rack-type supports or integrated into a building. These panels are connected in series or parallel to achieve optimal voltage and current, and feed into an inverter transforming direct current into alternating current at a phase and at the same voltage as the grid. The typical operating voltage of an array of panels is around 150-400 V DC for small systems (1-3 kW) and 400-700 V DC for inverters of 10-500 kW. Maximum voltage is generally limited on the one hand by problems of insulating panels to avoid any current leakage, and on the other hand by the maximum voltage accepted by the inverter. The inverter will be equipped with a maximum power point tracking (MPPT) system that constantly adjusts the entry voltage to the characteristics of the PV modules, which vary according to temperature and solar radiation.

This first chapter attempts to provide answers to basic questions on the nature of photovoltaic (PV) energy; on what it produces, at what cost and for what applications; and on the type of equipment needed in particular cases. All these points are dealt with in greater depth in the chapters that follow. In more general terms, we will consider the role of PV energy in sustainable development, for today this is a major challenge that can affect many of our choices.

Stand-alone PV generators are the oldest historically. They first appeared in the 1970s as solar panels mounted on satellites. These were soon followed by applications for rural pumping and electrification in developing countries, then domestic and technical stand-alone applications in industrialised countries. The reader will perhaps be surprised by the size of this chapter, which is disproportionate to the share of stand-alone in PV systems today. The length is justified by the fact that the stand-alone solar system is not just a PV generator but also includes energy storage, regulators and appliances specially developed for this purpose. Designing a stand-alone system often requires reviewing energy consumption and optimising it so as to only produce the essential energy necessary for the function to be supplied. In addition, the applications described in this chapter are highly diversified: stand-alone energy generation is attractive in a wide variety of circumstances, which is best to identify and deal with on a case-by-case basis.

In Chapter 2, certain PV materials such as crystalline and amorphous silicon have been described. Other materials apart from silicon can, however, be used. We consider here their nature, properties and potential uses. There are two major families of PV materials: Solid crystalline materials, Solid thin films (on a substrate). We also cover other technologies, in particular Gratzel-type dye-sensitised solar cells, polymer solar cells, cells containing small organic molecules and photoelectric chemical sensors. These technologies, while promising in terms of cost and adapt ability, have yet to show their competitiveness against the traditional technologies. Most have stability problems and have low efficiency (