Barry Rand1

1, Princeton University, Princeton, New Jersey, United States

Hybrid organic-inorganic halide perovskite materials such as methylammonium lead iodide have captured the interest of the thin film optoelectronics community due to their promising optoelectronic properties. For light emitting diodes (LEDs), we have established a general protocol to prepare ultrathin, smooth, passivated, and pinhole free films of metal halide perovskites with various compositions, by incorporating bulky organoammonium halide additives to the stoichiometric 3D perovskite precursors. LEDs produced in this way are capable of exceeding 17% external quantum efficiency, exhibit significantly improved stability, and are capable of being as flexible as organic electronic thin films. Finally, they allow for stabilizing mixed halide (I and Br) and mixed Pb-Sn stoichiometries such that we can tune emission from the green to near infrared.