Within the past decade perovskite solar cells (PSCs) have been a subject of intense research. The perovskite photo-absorptive materials offer inherent advantages leading to high power conversion efficiency, long carrier diffusion length, high carrier mobility, low exciton binding energy, high absorption coefficient and band gap tunability. These features, combined with the low-cost potential of the perovskite photovoltaic (PV) technology and the increasing electricity production from photovoltaic panels, the perovskite solar technology is expected to invade the conventional solar market first in tandem with existing silicon modules and later in low-cost panels of pure perovskite .
The possibility to deposit the perovskite thin films via solution-based processing enables high-throughput, cost-effective production of flexible and light-weight PSCs. This will further expand the commercialization potential of PSCs into variety of applications such as mobile electronic devices, vehicle- and building integrated PVs (VIPV, BIPV), building applied PV (BAPV) and Internet of Things (IoT) market. Despite the high power conversion efficiency (PCE) of 27.0% recorded for (rigid) perovskites at cell level, and stability surpassing the IEC certification standards, a successful implementation of the technology requires large-scale manufacturing methods reducing the production costs without the loss in efficiency.
The mainstream PV market is currently dominated by Asian producers of rigid crystalline silicon and glass-based PV products. Although these modules reach state-of-the-art efficiencies, their application areas are limited to surfaces that can bear the weight of the installed system and to areas not requiring customization (solar farms, rooftops). For broader application of PV, it is essential to apply them also on surfaces with aesthetic demands. Thus, flexibility in shape and size is a unique selling point of PSCs. Additionally, replacement of vacuum deposited metal electrodes with alternative, printable electrode (carbon) significantly reduces the CO2 footprint and the cost of the flexible perovskite PV.
The communication of European Commission strongly emphasizes the importance of bringing PV production back to Europe. One of the few competing areas that Europe can win is building up the processing infrastructure for flexible thin film photovoltaics, since this type of market product is not yet well established in the Asian factories. In PEARL, the participation of perovskite PV supplier partner Saule Technologies and their pioneering incentives on flexible perovskite PV is an important attempt to bring the PV production back to Europe.
The recent development of flexible PSCs has led to a world record efficiency of 24.9% by Tsinghua University, Beijing, China (doi: 10.23919/IEN.2024.0001). The primary objectives of PEARL are to realise flexible PSCs processed with industrially viable, scalable and environmentally sustainable thin film technologies, efficiency of >25% at cell and 22.5% at module level, showing long term operational stability surpassing the IEC standards, lowered production costs below 0.3 €/Wp, minimal emissions <0.01 kg CO2eq/kWh and high circularity through recycling of valuable materials. To reach the objectives, PEARL is focusing on the development of planar, conventional n-i-p, and further n-i-c, device architectures utilising low-temperature carbon pastes.
