Building Block‐Inspired Hybrid Perovskite Derivatives for Ferroelectric Channel Layers with Gate‐Tunable Memory Behavior

Abstract

Abstract Ferroelectric photovoltaics driven by spontaneous polarization ( P s ) holds a promise for creating the next‐generation optoelectronics, spintronics and non‐volatile memories. However, photoactive ferroelectrics are quite scarce in single homogeneous phase, owing to the severe P s fatigue caused by leakage current of photoexcited carriers. Here, through combining inorganic and organic components as building blocks, we constructed a series of ferroelectric semiconductors of 2D hybrid perovskites, (HA) 2 (MA) n‐1 Pb n Br 3n+1 ( n =1–5; HA=hexylamine and MA=methylamine). It is intriguing that their Curie temperatures are greatly enhanced by reducing the thickness of inorganic frameworks from MAPbBr 3 ( n =∞, T c =239 K) to n =2 ( T c =310 K, Δ T =71 K). Especially, on account of the coupling of room‐temperature ferroelectricity ( P s ≈1.5 μC/cm 2 ) and photoconductivity, n =3 crystal wafer was integrated as channel field effect transistor that shows excellent a large short‐circuit photocurrent ≈19.74 μA/cm 2 . Such giant photocurrents can be modulated through manipulating gate voltage in a wide range (±60 V), exhibiting gate‐tunable memory behaviors of three current states (“‐1/0/1” states). We believe that this work sheds light on further exploration of ferroelectric materials toward new non‐volatile memory devices.