Results and Discussions

Materials Characterizations of 2D MOFs

The detailed fabrication processes of the 2D Zn2(ZnTCPP) MOFs and the 2D-MOFs-based neuromorphic transistors are provided in the experimental section and Figure S1a. To prove that the Zn2(ZnTCPP) MOF was successfully prepared, we performed X-ray photoelectron spectroscopy (XPS) to characterize the as-prepared materials. As shown in Figure S1b and d, the Zn 2p signal at ~1017 eV and the N 1s signal at ~399.7 eV were observed, respectively, and the C 1s signal consisted of three parts (-COOH, -C2H2, and -C6H6) was also been observed (Figure S1c). The signals of these elements of the as-prepared materials are in good agreement with those observed in Zn2(ZnTCPP) MOFs reported in the literature\cite{hong2017}. In addition, X-ray powder diffraction (XRD) was also performed to characterize the as-prepared materials (Figure S2), which showed a similar XRD spectrum to the Zn2(ZnTCPP) MOFs reported in the literature\cite{jongens2005}, further confirming that the as-prepared materials are Zn2(ZnTCPP) MOFs. The bulk Zn2(ZnTCPP) MOFs were further dispersed into 2D Zn2(ZnTCPP) MOFs by using ultrasonication, and the sheet structure of the 2D Zn2(ZnTCPP) MOFs  was confirmed by the images from transmission-electron microscope (TEM) and atomic-force microscope (AFM) (Figure S3). 2D Zn2(ZnTCPP) MOFs were mixed with polymethyl methacrylate (PMMA) and uniformly distributed in the PMMA film, as confirmed by the XPS with Ar ion etching technique (Figure S4).