Organic–inorganic lead halide perovskite has recently emerged as an efficient absorber material for solution process photovoltaic (PV) technology, with certified efficiency exceeding 25%. The development of low-temperature (LT) processing is a challenging topic for decreasing the energy payback time of perovskite solar cell (PSC) technology. In this context, the LT planar n–i–p architecture meets all the requirements in terms of efficiency, scalability, and processability. However, the long-term stability of the LT planar PSC under heat and moisture stress conditions has not been carefully assessed. Here, a detailed study on thermal and moisture stability of large-area (1 cm2) LT planar PSCs is presented. In particular, the key role in thermal stability of potassium iodide (KI) insertion in the perovskite composition is demonstrated. It is found that defect passivation of triple-cation perovskite by KI doping inhibits the halide migration induced by thermal stress at 85 °C and delays the formation of degradation subproducts. T80, defined as the time when the cell retains 80% of initial efficiency, is evaluated both for reference undoped devices and KI-doped ones. The results show that T80 increases 3 times when KI doping is used. Moreover, an HTL-free architecture where the Au top electrode is replaced with low-T screen-printable carbon paste is proposed. The combination of the carbon-based HTL-free architecture and KI-doped perovskite permits T80 to increase from 40 to 414 h in unsealed devices.

Perovskite photovoltaics (PVs) is an emerging PV technology that attracts interest thanks to an unprecedented combination of properties, including the ease of the bandgap tunability. The feasibility to deploy wide bandgap absorbers (>2.2 eV) leading to high average visible transmittance (AVT) is particularly intriguing for building‐integrated PVs, in particular for smart windows, façades, and agrivoltaics. However, research on this topic is still at the initial stage, especially concerning the development of scalable deposition techniques. Uniform coverage and morphology control of bromide perovskite film are the main issues to tackle. Herein, a systematic study on the development of FAPbBr3‐based semi‐transparent perovskite solar cell (ST‐PSC) is presented by replacing spin‐coating as the main deposition technique used for the device fabrication. To tackle this topic, the blade coating technique is employed to obtain a manufacturing flow performed at low temperature in the air environment. The results for the blade‐coated device show a power conversion efficiency of 5.8%, AVT of 52.3%, and bifacial factor of 86.5%. Moreover, scalable and uniform FAPbBr3 deposition on 300 cm2 substrates is presented for the first time. The combination of low temperature, scale‐up capability, and air processing along with promising PV performances represent a feasible platform for the future exploitation of PSC in building integrated photovoltaic.

Our world is facing an environmental crisis that is driving scientists to research green and smart solutions in terms of the use of renewable energy sources and low polluting technologies. In this framework, photovoltaic (PV) technology is one of the most worthy of interest. Dye-sensitized solar cells (DSSCs) are innovative PV devices known for their encouraging features of low cost and easy fabrication, good response to diffuse light and colour tunability. All these features make DSSCs technology suitable for being applied to the so-called agrovoltaic field, taking into account their dual role of filtering light and supporting energy needs. In this project, we used 40 DSSC Z-series connected modules with the aim of combining the devices’ high conversion efficiency, transparency and robustness in order to test them in a greenhouse. A maximum conversion efficiency of 3.9% on a 221 cm2 active area was achieved with a transparency in the module’s aperture (312.9 cm2) area of 35%. Moreover, different modules were stressed at two different temperature conditions, 60 °C and 85 °C, and under light soaking at the maximum power point, showing a strong and robust stability for 1000 h. We assembled the fabricated modules to form ten panels to filter the light from the roof of the greenhouse. We carried out panel measurements in outdoor and greenhouse environments in both sunny and cloudy conditions to find clear trends in efficiency behaviour. A maximum panel efficiency in outdoor conditions of 3.83% was obtained in clear and sunny sky conditions.

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