Ice-confined synthesis of lecithin-protected perovskite microcrystals for stable optical synapses†

Perovskite microcrystals (PeMCs) show great potential for creating artificial optical synapses due to their low trap state density, high carrier mobility and high thermal stability. However, it is still a challenge to develop a green manufacturing process for preparing stable PeMCs. Here, we present a facile ice-confined strategy for achieving high-quality CsPbBr₃ PeMCs in pure water. In this method, lecithin protected PeMCs exhibited remarkable stability in polar solvents (water, ethanol, and acetone), which is due to the strong binding between lecithin and lead ions of PeMCs. Moreover, artificial optical synaptic transistors based on CsPbBr₃ PeMCs were successfully prepared. The devices successfully simulated visual functions by modeling important synaptic features such as excitatory postsynaptic currents, paired-pulse facilitation, spiking-rate-dependent plasticity, spiking-number-dependent plasticity and short-term memory to long-term memory transition. This work provides a new avenue for the synthesis of stable PeMCs and presents a new strategy for developing highly efficient artificial optical synaptic transistors.