Dye Molecule-Induced Optoelectronic Synaptic Behaviors of Monolayer MoSe₂

Although MoSe₂-based photodetectors have achieved excellent performance, the ultrafast photoresponse has limited their application as an optoelectronic synapse. In this paper, the enhancement of the rhodamine 6G molecule on the memory time of MoSe₂ is reported. It is found that the memory time of monolayer MoSe₂ can be obviously enhanced after assembly with rhodamine 6G exhibiting synaptic characteristics in comparison to pristine MoSe₂. Furthermore, the synaptic functions, including excitatory postsynaptic current, pair-pulse facilitation, short-term memory, long-term memory, "learning-experience" behavior, and tunable learning and forgetting process, can be achieved successfully. The distinctive energy-level structure of R6G and its excellent light absorption properties give MoSe₂ access to an additional source of electrons, thus enabling the proposed MoSe₂/rhodamine 6G hybrid heterostructure optoelectronic synapse to provide an efficient protocol for realizing optoelectronic neuromorphic computing and enormously facilitate the advancement of neuromorphic electronics.