Gas‐Assisted Spray Coating of Perovskite Solar Cells Incorporating Sprayed Self‐Assembled Monolayers

• Published in: Advanced science 2022-05, Vol.9 (14), p.e2104848-n/a
• Main Authors: Cassella, Elena J., Spooner, Emma L. K., Thornber, Timothy, O'Kane, Mary E., Catley, Thomas E., Bishop, James E., Smith, Joel A., Game, Onkar S., Lidzey, David G.
• Format: Article
• Language: English
• Subjects: Acids; air‐knife; Binding sites; Contact angle; Efficiency; Ethanol; gas‐quenching; perovskite solar cells; Polymer blends; scalable fabrication; self‐assembled monolayers; Solvents; spray coating
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202104848

Self‐assembled monolayers (SAMs) are becoming widely utilized as hole‐selective layers in high‐performance p‐i‐n architecture perovskite solar cells. Ultrasonic spray coating and airbrush coating are demonstrated here as effective methods to deposit MeO‐2PACz; a carbazole‐based SAM. Potential dewetting of hybrid perovskite precursor solutions from this layer is overcome using optimized solvent rinsing protocols. The use of air‐knife gas‐quenching is then explored to rapidly remove the volatile solvent from an MAPbI3 precursor film spray‐coated onto an MeO‐2PACz SAM, allowing fabrication of p‐i‐n devices with power conversion efficiencies in excess of 20%, with all other layers thermally evaporated. This combination of deposition techniques is consistent with a rapid, roll‐to‐roll manufacturing process for the fabrication of large‐area solar cells. Carbazole‐based self‐assembled monolayers are becoming a dominant hole‐transporting layer in p‐i‐n perovskite solar cells, combining stability, efficiency, and low‐cost. Here, spray coating and airbrush pen coating of MeO‐2PACz are used to fabricate high‐quality transport layers. This is combined with gas‐quenched spray‐coated perovskite layers, to realize solar cells with power conversion efficiencies in excess of 20%.