Our optoelectronics neuromorphic transistors were fabricated by using the 2D Zn2(ZnTCPP) MOFs -PMMA film as the charge trapping layer. The cross-section scanning-electron microscope (SEM) characterization of the device structure is shown in Figure S3b. The thickness of the charge trapping layer is about 30 nm. The thickness is consistent with the AFM results (Figure S5). The evaporated pentacene on the charge trapping layer displayed a typical island-growth layer-like structure, as shown in Figure S5c. To characterize the optical properties of the 2D Zn2(ZnTCPP) MOFs -PMMA film and the pentacene film, we performed ultraviolet-visible spectroscopy (UV-vis) analysis, as shown in Figure S6a. The absorption peaks of the 2D Zn2(ZnTCPP) MOFs -PMMA film and the pentacene film were located at ~430 nm and ~660 nm, respectively. The steady-state photoluminescence (PL) spectrums and the PL decay profiles of the 2D Zn2(ZnTCPP) MOFs -PMMA film   and the 2D Zn2(ZnTCPP) MOFs -PMMA film/pentacene film were presented in Figure S6b and 6c. Compared with the 2D Zn2(ZnTCPP) MOFs-PMMA/pentacene film, the 2D Zn2(ZnTCPP) MOFs -PMMA film exhibited stronger emission peaks in the orange and red regions under excitation at 405 nm wavelength. The PL decay curve of the 2D Zn2(ZnTCPP) MOFs-PMMA was well-fitted by a bi-exponential decay function, which presents two relaxation mechanisms, the lifetime of fast decay (τ1) and short decay (τ2).  The fitting result can be quantified as τ1 = 1.1 ns and τ2 = 6.7 ns, respectively, while the profile of 2D Zn2(ZnTCPP) MOFs-PMMA film/pentacene film exhibits a shorter decay time (τ1 = 1.0 ns and τ2 = 4.6 ns) due to the photo-induced charge transfer effect. Before the demonstration of the essential emotion-tunable neuromorphic functions, the basic transfer performance (Figure S7) and the synaptic behaviors of this device werecharacterized.

Basic Synaptic Performance of MOF-based Device

In the biological synapse, the external stimulus is transmitted and processed by neurons and synapses (Figure \ref{941862}). The transmission rate of the signal flow depends on the number and the activity of the acceptors\cite{ehlers2005,fuxe1999}. Therefore, the post membrane with few and low-activity acceptors would induce a low post-synaptic current, which results in a weak signal response to the external stimulus. Compared with the low-activity synapse, the post membrane with more acceptors would trigger enhanced post-synaptic plasticity because more acceptors can be excited by the transmitters. The photo-responsiveness of our neuromorphic device can be controlled by the source-drain voltage (VDS), which means that the effect of VDS on synaptic devices is similar to that of the number of receptors on the postsynaptic membrane. Therefore, we can use VDS to modulate our device performance.