Journal Article 2D molecular crystals p-n heterojunctions All‐optical convolution computing Review artificial spiking neural network artificial synapses bidirectional phototransistors bulk heterojunctions display electrochemical reactions long‐afterglow emission microspacing in-air sublimation negative photoresponse neuromorphic display neuromorphic technology non‐von Neumann architecture organic field‐effect transistor organic phototransistors organic vertical transistors photoelectronic synapses photoluminescent device steep switching ultralow power consumption ultralow voltage visual adaption