2D perovskite stabilized phase-pure formamidinium perovskite solar cells.

ABSTRACT: Compositional engineering has been used to overcome difficulties in fabricating high-quality phase-pure formamidinium perovskite films together with its ambient instability. However, this comes alongside an undesirable increase in bandgap that sacrifices the device photocurrent. Here we report the fabrication of phase-pure formamidinium-lead tri-iodide perovskite films with excellent optoelectronic quality and stability. Incorporation of 1.67?mol% of 2D phenylethylammonium lead iodide into the precursor solution enables the formation of phase-pure formamidinium perovskite with an order of magnitude enhanced photoluminescence lifetime. The 2D perovskite spontaneously forms at grain boundaries to protect the formamidinium perovskite from moisture and suppress ion migration. A stabilized power conversion efficiency (PCE) of 20.64% (certified stabilized PCE of 19.77%) is achieved with a short-circuit current density exceeding 24?mA?cm^-2 and an open-circuit voltage of 1.130?V, corresponding to a loss-in-potential of 0.35?V, and significantly enhanced operational stability.

SUBMITTER: Lee JW 

PROVIDER: S-EPMC6070510 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature