Indium-tin oxide (ITO) thin layers are obtained by an IBS (Ion Beam Sputtering) deposition process. We elaborated ITO films on flexible substrates of polyethylene terephthalate (PET), under soft conditions of low temperatures and fulfilling the requirements of fabrication processes of the organic optoelectronic components. With a non thermally activated (20 °C) ITO deposition assisted by an oxygen flow (1 cm3/min), we got an optical transmittance of 90% in the visible range, a resistivity around 10−3 Ω.cm and a surface roughness lower than 1.5 nm. Thus we realized flexible organic light-emitting diodes (FOLEDs) with good performances: a maximum luminance of 12000 cd/m2 at a voltage of 19 V and a maximum luminous power efficiency around 1 lm/W at a voltage of 10 V (or a maximum current efficiency of 4 cd/A at 14 V) for the (PET(50 μm)/ITO(200 nm)/TPD(40 nm)/Alq3(60 nm)/Ca/Al) structure.

This work explores the utilization of plasmonic resonance (PR) in silver nanowires to enhance the performance of organic solar cells. We investigate the simultaneous effect of localized surface plasmon resonance (LSPR), surface plasmon polariton (SPP), and waveguide plasmonic mode on silver nanowires, which have not been thoroughly explored before. By employing finite-difference time-domain (FDTD) simulations, we analyze the plasmonic resonance behavior of a ZnO/Silver nanowires/ZnO (ZAZ) electrode structure. Our investigations demonstrate the dominance of LSPR, leading to intense electric fields inside the nanowire and their propagation into the surrounding medium. Additionally, we observe the synergistic effects of SPP and waveguide plasmonic mode, contributing to enhanced light absorption within the active layer of the organic solar cell. This leads to an improvement in photovoltaic performance, as demonstrated by our previous work, showing an approximate 20% increase in photocurrent and overall power conversion efficiency of the organic solar cell. The incorporation of metallic nanostructures exhibiting these multiple plasmonic modes opens up new opportunities for improving light absorption and overall device efficiency. Our study highlights the potential of these combined plasmonic effects for the design and optimization of organic solar cells.

Light effect on electrical properties of a pentacene-based transistor was studied. We showed that under optical excitation, the phenomenon of photoconductivity can modify both carrier density and mobility; these changes depend on the wavelength, on the carrier photogeneration rate and on the material absorption coefficient. At first, we examined structural, optical and electrical properties of pentacene films; a thickness of 50 nm is the good compromise to obtain optimal performances. Then we observed the effect of illumination on the drain current in the accumulation regime: at 365 nm, we obtained a maximum ratio of photocurrent to dark current (Idsillumination/Idsdark) of about 2 × 103 when the gate is turned off, mobility and threshold voltage values around 0.02 cm2 V−1 s−1 and 7.5 V respectively. Moreover the dynamics study (off-state) showed sufficiently fast response times with large current gains to envisage applications in the area of light activated memory components. Finally, we examined the performances of a new component based on the coupling of an organic light emitting diode (with an emission peak at 550 nm) as an input unit with an organic transistor as an output unit. This last study enabled to underscore an increase in mobility without modifying the carrier density for low carrier photogeneration rates.