  Perovskite light-emitting field-effect transistors (PeLEFETs) provide a
versatile device architecture to control transport and electroluminescence
properties of hybrid perovskites, enabling injection of high charge carrier
density and spatial control of the radiative recombination zone. Ionic
screening and organic cation polarization effects typical of metal-halide
perovskites, however, critically affect PeLEFET efficiency and reliability. In
this work, we demonstrate a new device operation mode based on high-frequency
modulation of the applied voltages, which allows significant reduction of ionic
drift/screening in methylammonium lead iodide light-emitting transistors. In
optimized top contact PeLEFETs, AC operation results in brighter and more
uniform electroluminescence compared to DC-driven devices. Moreover, high
frequency modulation enables electroluminescence emission up to room
temperature.
