Toward a Full Slot-Die-Coated Green Solvent Ink Perovskite Solar Cell

Perovskite Solar Cells (PSC) have potential as thin film photovoltaic technology due to their high efficiency and low cost compared with similar technologies. However, the efficiency in large-area modules of perovskite photovoltaics (PPV) is still significantly lower than the power conversion efficiency (PCE) in silicon solar cells, representing an opportunity to achieve large-scale devices with better performance¹. In this sense, Slot-Die Coating (SDC) is one of the best options for reaching efficient large-area devices since it allows the processing of several layers and enables the manufacture of rigid and flexible devices. As a continuous manufacturing method, SDC still has significant obstacles to overcome, especially regarding device reproducibility and stability, especially when the devices are manufactured under ambient conditions².<br/>It is expected to find information concerning the adverse effects of water on the stability of PSC devices, especially in the perovskite layer ^3–5. However, it has been demonstrated that water in perovskite precursor did not negatively impact the perovskite thin-film preparation process and enabled perovskite's humidity tolerance under ambient conditions fabrication⁶. Water can also help prolong the film-drying process, forming perovskite thin films with large grain sizes by depositing them with pre-metered methods such as SDC and DBC.<br/>On the other hand, existing reports⁷ place planar structures as among the most widely used structures for scaling PSCs because the simple structure of planar PSC devices does not need to prepare mesoporous layers, which can save cost and time. Also, it has a high conversion efficiency⁸, and the p-i-n structure can be manufactured at low temperatures⁹. Nevertheless, it is also well known that the increment in the area leads to defects that decrease the PCE, which turns the interlayers into an excellent tool to achieve better devices.<br/>This work is focused on scaling the perovskite layer on a planar structure, using the SDC nickel oxide (NiO_x) layer as hole transfer material and a self-assembled monolayer (SAM) to improve the interaction with the perovskite layer. In addition, we use an SDC water-based MAPbI₃ formulation, which is processable under ambient conditions, reaching efficiencies around 10% approaching the scaling of PSC to room temperature manufacturing conditions and using green solvent inks for the active layer.<br/><br/>1. Patidar, R., Burkitt, D., Hooper, K., Richards, D. & Watson, T. Slot-die coating of perovskite solar cells: An overview. <i>Mater. Today Commun.</i> <b>22</b>, 100808 (2020).<br/>2. Roy, P., Ghosh, A., Barclay, F., Khare, A. & Cuce, E. Perovskite Solar Cells: A Review of the Recent Advances. <i>Coatings</i> <b>12</b>, (2022).<br/>3. Jonathan, L. <i>et al.</i> Hybrid Organic Inorganic Perovskite Halide Materials for Photovoltaics Towards Their Commercialization. <i>Polymers (Basel).</i> <b>14</b>, (2022).<br/>4. Li, J. <i>et al.</i> 20.8% Slot Die Coated MAPbI3 Perovskite Solar Cells by Optimal DMSO-Content and Age of 2 ME Based Precursor Inks. Supporting information. <i>Adv. Energy Mater.</i> <b>11</b>, (2021).<br/>5. Wei, J. <i>et al.</i> Highly Stable Hybrid Perovskite Solar Cells Modified with Polyethylenimine via Ionic Bonding. <i>ChemNanoMat</i> <b>4</b>, 649 655 (2018).<br/>6. Liu, D. <i>et al.</i> Aqueous Containing Precursor Solutions for Efficient Perovskite Solar Cells. <i>Adv. Sci.</i> <b>5</b>, 1700484 (2018).<br/>7. Cai, X. <i>et al.</i> A review for nickel oxide hole transport layer and its application in halide perovskite solar cells. (2023) doi:10.1016/j.mtsust.2023.100438.<br/>8. 20.8% Slot Die Coated MAPbI3 Perovskite Solar Cells by Optimal DMSO Content and Age of 2 ME Based Precursor Inks. https://onlinelibrary.wiley.com/doi/epdf/10.1002/aenm.202003460.<br/>9. Ma, F., Zhao, Y., Qu, Z. & You, J. Developments of Highly Efficient Perovskite Solar Cells. <i>Accounts Mater. Res.</i> (2023) doi:10.1021/accountsmr.3c00068.