At the National Renewable Energy Laboratory (NREL), scientists have been exploring the mineral perovskite as a cheaper, more efficient replacement for silicon in photovoltaic cells.
In one test, researchers combined perovskite with carbon nanotubes and shot a laser at the new material. They should have seen a blip of electricity from the combination.
Instead, the current flowed out of the alloy for more than an hour, well after the laser was shut off.
This strange “optical memory,” in which a material can store light as an electric current, had only been seen before under high voltages and unnaturally low temperatures. In the past, materials also have “remembered” the light as current for a fraction of a second.
But in NREL’s test, the lingering memory took place at room temperature with a low voltage and a low light intensity.
The scientists realized this is similar to the workings of a neuron in the brain: it collects data as a burst of energy and then transmits that news out through a network of other neurons to form a memory, answer the phone, or avoid tripping over the dog.
NREL is now testing arrays of these connected artificial neurons as memory devices.
TRENDPOST: In the short term, NREL’s new phototransistor could have applications for optical memory arrays in computers or as guidance sensors in self-driving cars.
But the greater implication is for tomorrow’s computers that combine these devices with artificial intelligence and quantum computers running on light, eventually giving devices the size of a tablet the power of today’s supercomputers.

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