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

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 manufacture for preparing stable PeMCs. Here, we present a facile ice-confined strategy for achieving high-quality CsPbBr3 PeMCs in pure water. In this method, the lecithin protected PeMCs exhibited remarkable stability in polar solvent (water, ethanol, and acetone), which is due to the strong binding ability between lecithin and lead ions of PeMCs. Moreover, the artificial optical synaptic transistors based on CsPbBr3 PeMCs were successfully prepared. The device 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 points to a new strategy for highly efficient artificial optical synaptic transistors.