Synapse-Like Phototransistor Enables Persistent, Low-Energy Optical Switching

Researchers at the U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) created a phototransistor that allows long-lived persistent photoconductivity (PPC), which is a form of optical memory. The new structure is a heterojunction between perovskite semiconductors and carbon nanotubes. The device could enable optical switching with low energy consumption for potential use in sensors and artificial neural networks and in applications such as self-driving vehicles. The researchers combined metal-halide perovskite nanocrystals with a network of single-walled carbon nanotubes to make the device. They tested three types of perovskites — formamidinium lead bromide, cesium lead iodide, and cesium lead...