Flexible transparent conducting electrodes unexpectedly influence MAPbI3 film morphology and perovskite solar cell performance

Fabricating perovskite solar cells (PSCs) on plastic substrates will enable cost-effective manufacturing of lightweight and portable energy systems. Here, we study the influence of flexible transparent conductive electrodes (TCEs) on the methylammonium lead iodide (MAPbI 3 ) film morphology and PSC performance. Three types of TCEs on polyethylene terephthalate (PET) are compared: a custom-made AgNWs/indium zinc oxide hybrid TCE and two commercial substrates with indium tin oxide (ITO) or metal/insulator/metal (MIM) as the TCE. Using the same p - i - n architecture and hole transport layer (HTL), we find that PSCs fabricated on the hybrid TCE show better performance and stability compared to those made on commercial TCEs. The PSC performance enhancement is attributed to the superior structural and optical properties of MAPbI 3 film deposited on the hybrid TCE, which is explained by the surface energy difference of the HTL. While it is anticipated that solar cell performance can be affected by TCEs’ transmittance and sheet resistance as they determine light absorption and carrier transport, respectively, our finding of TCE influencing the morphology and crystallinity of MAPbI 3 film, and hence PSC performance, is unexpected. • Perovskite solar cells on PET/AgNWs/IZO TCE show superior performance. • The choice of PET/TCEs affects perovskite film morphology and properties. • The same HTL deposited on different PET/TCE exhibits varying surface energies. • Superior MAPbI 3 morphology observed for the hybrid TCE with lowest surface energy. • PET/TCE affects MAPbI 3 film properties, which affects solar cell performance.