“…To date, a variety of photoactive materials have been explored, including inorganic and hybrids, – conjugated molecules, , natural chromophores, , or conjugated/insulating polymers, – for light harvesting in semiconducting channels or embedded in dielectric to ensure signal transmission of artificial synapses. A wide range of proposed device architecture approaches, including (i) a photogate-embedded composite semiconducting channel; – (ii) a photoactive electret beneath the semiconducting channel; , and (iii) a photogate-embedded insulating electret beneath the semiconducting channel, , all of which exploit this phenomenon by altering the conductance level in semiconducting channels through photoexcitation-induced charge transfer. For the optical stimulation aspect thereof, the most prominent forms of synaptic functionality are realized regarding photoexcitatory potentiation of synaptic weight in two major ways: short-term plasticity (STP) and long-term plasticity (LTP) triggered by excitatory postsynaptic current (EPSC) enhancement for all types of photosynaptic transistors. , Indeed, a rehearsal learning process of the human brain was mimicked to test the dynamic visual learning/forgetting behavior of photosynaptic transistors, which is influenced by the synaptic weight along with the rate and number of pulses, pulse intensity, pulse width, and wavelength, such as brain activity during learning, depending on the frequency, time, and intensity of data rehearsal .…”