Recent advances in fiber-shaped and planar-shaped textile solar cells

During the last few years, textile solar cells with planar and fiber-shaped configurations have attracted enormous research interest. These flexible-type solar cells have a huge potential applicability in self-powered and battery-less electronics, which will impact many sectors, and particularly the Internet of Things. Textile solar cells are lightweight, super-flexible, formable, and foldable. Thus, they could be ideal power-harvester alternatives to common flexible solar cells required in smart textiles, electronic textiles, and wearable electronic devices. This review presents a brief overview on fiber-shaped and planar-shaped solar cells, and it introduces the most recent research reports on the different types of textile solar cells, including details on their fabrication techniques. It also addresses the current challenges and limitations of their technology development, and the encountered issues for their future application and integration in novel devices.acceptedVersionPeer reviewe

Perovskite solar cells : stability lies at interfaces

Perovskite solar cells are developing fast but their lifetimes must be extended. Now, large-area printed perovskite solar modules have been shown to be stable for more than 10,000 hours under continuous illuminatio

Solid state dye sensitized solar cells applying conducting organic polymers as hole conductors

Solid-state dye sensitized solar cells (SSDSCs) applying mesoporous TiO electrodes sensitized with Ru complex dye Z907 and conducting organic polymers as the hole transport material (HTM) are prepared. We employ the in-situ photo-electrochemically polymerization technique (PEP)[1-3] in order to obtain, in a single step, the conducting organic polymer on the TiO /Dye electrode. We developed a modification of reported method [2] which allows the polymer poly(3,4-ethylenedioxythiophene) (PEDOT) by different electrochemical techniques applying constant-voltage and constant-current methods. Polymer morphology and its influence on solar cell performance were studied. Overall conversion efficiency above 2% (AM 1.5, 100 mW cm) was obtained

Effect of testing conditions on the photovoltaic performance of ZnO-based dye sensitized solar cells

Dye-sensitized solar cells based on vertically-aligned ZnO nanorod, were analyzed at different conditions. Stability tests showed an improvement on solar conversion efficiency between ∼20% (1000 W/m) and ∼50% (1800 W/m). This behavior was ascribed to the physisorption/ chemisorption of the N-719 dye on the ZnO due to UV light. Studies at different temperatures proved that the performance of the cells can double when decreasing temperature from 72°C to room temperature. An increase on the efficiency and decrease in FF was observed when light intensity is increased. IPCE analyses were used to monitor the stability of the solar cells with time

Application of MEH-PPV/SnO2 bilayer as hybrid solar cell

The applications of conducting organic polymers in combination with semiconductor oxides are promising candidates as active materials for air-stable hybrid electronic applications such as transistors, light emitting diodes or organic photovoltaics. In this work, we report our last results on the application of SnO thin films in all solid-state hybrid solar cells. We also compare the results with other five solar cells developed in our laboratories applying MEH-PPV and semiconductor oxides like TiO, NbO, ZnO, CeO or CeO-TiO . In this work, SnO thin films, obtained from sol-gel solutions, have been applied in HSC in a configuration ITO/SnO /MEH-PPV/Ag. The effects of factors, such as UV light, polymer thickness, stabilization in the dark and performance under irradiation conditions, have been investigated. Open circuit voltage and short circuit current values were about -0.45 V and 0.17 mA/cm, with fill factors around 30%. Photoaction spectra show the activity of the semiconductor oxide below 340 nm and about 490 nm for the polymer. Lifetime behavior of the HSC showed an initial increase in current density reaching a maximum after about 1 h of irradiation. Blocking the UV-wavelength range by the application of a filter showed no significant difference in HSC properties with respect to the sample without UV filter. Comparison with other 5 semiconductor oxides revealed a direct relation between semiconductor oxide applied and V from the solar cell

Above-Bandgap Photovoltages in Antiferroelectrics

Altres ajuts: COST Action StableNextSol project MP1307The closed circuit photocurrent and open circuit photovoltage of antiferroelectric thin films were characterized both in their ground (antipolar) state and in their polarized state. A sharp transition happens from near zero to large photovoltages as the polarization is switched on, consistent with the activation of the bulk photovoltaic effect. The AFE layers have been grown by a solution processing method (sol?gel synthesis followed by spin coating deposition) onto fluorine-doped tin oxide (FTO), a transparent conducting oxide with low sheet resistance and a higher resilience to high-temperature processing than indium tin oxide and a standard for solar cells such as organometal trihalide perovskites. Light absorption confirmed that the PZO films are, as expected, wide-band gap semiconductors with a gap of 3.7.8 eV and thus highly absorbing in the near-ultraviolet range. On a virgin sample, there is no shortcircuit photocurrent, consistent with the antipolar nature of the ground state. As an external bias voltage is applied, the current remains negligible until suddenly, at the coercive voltage, a spike is observed, corresponding to the transient displacement current caused by the onset of polarization

Electrochemically synthesized mesoporous thin films of ZnO for highly efficient dye sensitized solar cells

Abstract In this work, nanostructured thin films of ZnO were electrochemically grown on FTO substrates. The morphology was tuned by modifying the synthesis parameters. The synthesis was carried out by applying Zn(NO3)·6H2O as the sole component of the aqueous electrolyte, avoiding the use of capping agents. The composition and morphology of the prepared ZnO were characterized by energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM), respectively. The as-deposited films were applied as electrodes in dye sensitized solar cells (DSCs). The performance of the cells was investigated by J×V curves and IPCE (incident photon to charge carrier efficiency) measurements. The SEM analysis demonstrated a direct relationship between ZnO morphology and Zn precursor concentration. It has been shown that the lower the concentration is, the more porous the morphology is. Increasing the amount of dye adsorbed on the ZnO decreased the power conversion efficiency of the final DSCs. The best cell presented the following parameters: open circuit voltage VOC=0.59V, short circuit current JSC=7.64mA/cm2, fill factor FF=50.41%, and power conversion efficiency PCE=2.27%

Enhancement of TiO2 nanoparticle properties and efficiency of dye-sensitized solar cells using modifiers

A low-temperature hydrothermal process developed to synthesizes titania nanoparticles with controlled size. We investigate the effects of modifier substances, urea, on surface chemistry of titania (TiO) nanopowder and its applications in dye-sensitized solar cells (DSSCs). Treating the nanoparticles with a modifier solution changes its morphology, which allows the TiO nanoparticles to exhibit properties that differ from untreated TiO nanoparticles. The obtained TiO nanoparticle electrodes characterized by XRD, SEM, TEM/HRTEM, UV-VIS Spectroscopy and FTIR. Experimental results indicate that the effect of bulk traps and the surface states within the TiO nanoparticle films using modifiers enhances the efficiency in DSSCs. Under 100-mW cm simulated sunlight, the titania nanoparticles DSSC showed solar energy conversion efficiency = 4.6 %, with V = 0.74 V, J = 9.7324 mA cm, and fill factor = 71.35

Low-temperature, solution-processed, layered V2 O5 hydrate as the hole-transport layer for stable organic solar cells

Layered V O hydrate has been applied as the hole transport layer (HTL) in organic solar cells (OSCs). V O is obtained from a sodium metavanadate solution in water under ambient conditions, resulting in a final thin film of formula V O ·0.5H O. The 0.5 water molecules are not removed from the V O layered structure unless the sample is heated above 250 °C, which makes the thin film highly stable under real working conditions. The HTL was used in OSCs in the normal and the inverted configurations, applying metallic Ag as the back-metal electrode in both cases. Fabrication of both OSC configurations completely by solution-processing printing methods in air is possible, since the Al electrode needed for the normal-configuration OSC is not required. The work function (WF) and band gap energy (BG) of the V O thin films were assessed by XPS, UPS and optical analyses. Different WF values were observed for V O prepared from a fresh V O -isopropanol (IPA) solution (5.15 eV) and that prepared from a 24 h-old solution (5.5 eV). This difference is due to the gradual reduction of vanadium (from V to V ) in IPA. The OSCs made with the V O thin film obtained from the 24 h-old V O -IPA solution required photo-activation, whereas those made with the freshly obtained V O did not. Outdoor stability analyses of sealed OSCs containing a V O HTL in either configuration revealed high stability for both devices: the photovoltaic response at T was retained for more than 1000 h