A Comparison of the Structure and Properties of Opaque and Semi-Transparent NIP/PINâType Scalable Perovskite Solar Cells

Abstract

For over a decade, single-junction perovskite solar cells (PSCs) have experienced an unprecedent increase in efficiencies and even offer opportunities to surpass the Shockley-Queisser limit in multijunction configuration. There is consequently an intense need for easily processable semiâtransparent PSCs as a basis of affordable tandems. The current study reports the comparison of negativeâintrinsicâpositive (NIP) and positiveâintrinsicânegative (PIN) architectures based on CH3NH3PbI3{Cl}-based perovskite. Both devices could be prepared with the same Nâtype (SnO2 nanoparticles) and Pâtype (polyâtriarylamine (PTAA) polymer) materials. Each layer (except for electrodes) was deposited using solventâbased low temperature processes, contrasting with other literature studies, especially SnO2 for PIN-type purposes. A thorough experimental comparison of the two architectures reveals rather similar optical and structural properties for perovskites, whether deposited on an N-or P-type underlayer, with also comparable efficiencies in the final devices. A compatible deposition process for sputtered indium tin oxide (ITO) as a semiâtransparent electrode was then performed for both architectures. Upon varying the illuminated devices' side, the semiâtransparent cells exhibited different photocurrent behaviors, the magnitude of which depended on the device's architecture. In conclusion, despite slightly better efficiencies for the semitransparent NIPâtype devices, the semiâtransparent PINâtype counterparts also appear to be optically attractive for (two-terminal) tandem applications.