Improving Performance of Nonvolatile Perovskite‐Based Photomemory by Size Restrain of Perovskites Nanocrystals in the Hybrid Floating Gate

Perovskite‐based photomemory adopting a floating‐gate architecture recently attracts research attention for developing efficient photo‐recording devices due to its simplified structure and non‐contact light‐programming feature. Herein, the memory characteristics of such type device is improved by the precise control of the size of perovskite nanocrystals (NCs) in the hybrid floating gate. Compared to the previous case of using polystyrene (PS) as the host polymer matrix, a N‐containing polymer, poly(2‐vinyl pyridine) (P2VP), is revealed to better regulate the size of embedded perovskite NCs into the nanometer level (7–9 nm) owing to the intense coordination between the N atom in P2VP and the Pb2+ ions of perovskite through Lewis acid‐base interaction. As benefitting from the reduced current dissipation and interfacial charge recombination at the gate/channel interface, the P2VP‐derived photomemory not only delivers a much higher On/Off current ratio (105) than the value (103) of the reference PS‐based device but also requires a much shorter illumination time (5 s) and low drain voltage (‐1 V) to achieve decent photo‐recording function. Besides, it possesses good long‐term retention for 104 s, excellent stress endurance over 100 cycles, and respectable ambient stability over 6 months due to the well isolation of perovskite NCs in the P2VP matrix. The nonvolatile memory behavior of perovskite‐based photomemory is shown to be improved by size restrain of perovskite nanocrystals (NCs) in the hybrid floating gate. By replacing poly(2‐vinylpyridine) (P2VP) with polystyrene (PS), the embedded perovskite CH3NH3PbBr3 NCs become smaller along with a more uniform distribution inside the hybrid film, leading to a much improved photo‐recording function.