Organolead trihalide perovskite solar cells based upon the co-deposition of a combined Al2O3-perovskite layer at T < 110 °C are presented. We report an average PCE = 7.2% on a non-sintered Al2O3 scaffold in devices that have been manufactured from a perovskite precursor containing 5 wt% Al2O3 nanoparticles.

transparent conducting contact adhesive that can be applied to perovskite based devices providing conductivity, charge extraction, mechanical adhesion and protection. This has allowed indium-tin oxide (ITO), Au and Ag free entirely non-vacuum processed PSC devices to be fabricated with a solar-to-electrical power conversion effi ciency (PCE) of over 15%.There are some excellent alternatives to replace thermally evaporated silver and gold electrodes in third generation photovoltaic devices, such as solid-state Dye Sensitized Solar Cells (s-DSC) and Organic Photovoltaics (OPV) based on the use of solution processed silver nanowires. [6][7][8] In these situations comparable performance has been achieved to vapor deposited electrodes. Prior to these developments, nanoparticulate silver inks deposited onto the photovoltaic (PV) devices with subsequent heating of the whole device to 150-200 °C were a route to applying the conductor via printing. [ 9 ] This can cause degradation of temperature sensitive components within the devices, such as the hole transporter which is commonly used (Spiro-OMeTAD) with a resultant loss of PV performance. Silver nanowires are advantageous in this respect as the heating step to anneal the nanowires can be conducted separately before being applied onto the devices at room temperature. This is due to the nanowire mesh's low sheet resistance and a good electrical contact made with the cells. [ 6 ] There are however issues with the use of silver based conductors in contact with the PSC since the halide content can give rise to silver halide formation and degradation of performance and we sought a different solution for PSCs.The currently reported high effi ciencies of 12-15% for PSCs have been achieved with a vapor deposited precious metal contact (usually gold). Silver based coatings could suffer from degradation through the formation of silver halides leading to a contact breakdown with the Spiro-OMeTAD. [ 10 ] In order to develop an indium and precious metal free transparent conductor we have combined a corrosion proof Ni mesh electrode (embedded in a PET fi lm) with a silver-free transparent conducting adhesive (TCA). The whole electrode can be fabricated separately to the organic-inorganic lead halide perovskite photoelectrode and then simply laminated at room temperature.The transparent electrode material was obtained from Epigem and is a Ni mesh embedded in a PET fi lm on a roll to roll process; this produces a robust and highly conductive electrode at less than half the cost of ITO PET. The mesh spacing is ca 300 µm, and the PET fi lm with the mesh is 86% transparent and is shown in Figure 1 a. The mesh electrode has extremely A key challenge that can unlock the potential of third generation photovoltaics (PV) is the development of low cost indium free fl exible transparent electrodes to enable lightweight, transparent and metal mounted devices. Here we describe a major breakthrough which allows a highly conducting self-adhesive laminate electrode to be applied to devices at room t...

T. (2017). One-step deposition by slot-die coating of mixed lead halide perovskite for photovoltaic applications. Solar Energy Materials and Solar Cells, 159,[362][363][364][365][366][367][368][369] http://dx. AbstractRecent advances in the performance and stability of lead halide perovskite solar cells announce a promising future for this technology. As the understanding of lab scale device fabrication progresses technology developments in the area of up-scaling are required to demonstrate their viability on an industrial and pre-commercial scale. These developments include replacing slow spin coated deposition techniques with continuous roll to roll compatible slot-die methods. In this work we demonstrate the suitability of a one-step slot-die coating method for the deposition of lead halide perovskite layers, in particular for infiltration into a mesoporous titania scaffold. Appropriate crystallisation dynamics of the perovskite are achieved by careful control of the substrate temperature in combination with a post-processed rapid air knife application. We show that devices fully processed in air using this method deliver a photovoltaic conversion efficiency up to 9.2% , this is comparable to those manufactured using a spin coating process.

The origins of recombination processes, particularly those that relate to current−voltage hysteresis, are still unclear in perovskite solar cells. Of particular interest is the impact different contact materials have on the level of hysteresis observed. This work shows that there is a clear link between ionic movement and interfacial recombination, which have both been shown to be responsible for hysteresis. When low-temperature transient photovoltage (TPV) measurements are performed over a period in which ions redistribute within the perovskite layer, the dominant recombination mechanism, responsible for hysteresis and other slow dynamic processes, is found to occur at the TiO 2 /perovskite interface. We observe an anomalous negative transient upon firing the laser pulse, which we attribute to interfacial recombination at the TiO 2 /perovskite interface. The impact of recombination at the perovskite/ HTL interface is shown to be negligible by performing TPV measurements using different laser wavelengths to probe different depths into the perovskite layer, as well as by changing the type of HTL used.

Flexible perovskite solar cells with power conversion efficiencies of up to 10.3% have been prepared using titanium foil as an electrode substrate.