Memory properties of (110) preferring oriented CH3NH3PbI3 perovskite film prepared using PbS-buffered three-step growth method

作者：Wu Hsuan Ta; Chen Yung Fu; Shih Chuan Feng; Leu Ching Chich^*; Wu Shih Hsiung

来源：Thin Solid Films, 2018, 660: 320-327.

DOI：10.1016/j.tsf.2018.06.032

• CH3NH3PbI3
• PbS-buffered growth
• Texture
• Resistive random access memory

We proposed a PbS-buffered method to fabricate the (110)-textured CH3NH3PbI3 (MAPbI(3)) film by three-step conversion (PbS -> PbI2 -> MAPbI(3)). The PbS buffer layer comprised numerous polyhedron particles was prepared on top of the Glass/indium tin oxide (ITO) via a chemical bath deposition process. Firstly, the PbS was converted to PbI2 by I-2 gas annealing that caused a dense and (001)-preferred PbI2. Secondly, the PbI2 was turned into a MAPbI(3) film by MAI vapor annealing, of which the degree of preferring orientation of the (110) face was higher and the micrometer grains was more compact than that was prepared by the conventional two-step (PbI2 -> MAPbI(3)) spin-coated MAPbI(3). The dense and (001)-textured PbI2, which was converted from the PbS with an appropriate condition, was the key to obtain the (110)-preferred MAPbI3 with a good quality. For comparative study, the memory devices (Glass/ITO/MAPbI(3)/poly methyl methacrylate (PMMA)/Al) made by the PbS-buffered MAPbI(3) and the spin-coated MAPbI(3) were both studied. As a result, both of them showed bipolar resistive switching behaviors with an ON/OFF ratio of similar to 10(2); whereas the leakage current of the PbS-buffered MAPbI(3) sample was 3 orders lower than that of the spin-coated one. The large crystalline grain, high-compact structure and (110) preferred texture of the PbS-buffered MAPbI(3) were believed to contribute to such a low leakage current, which is beneficial for the memory application.

• 出版日期2018-8-30