Perovskite Nanocrystal—Carbon Nanotube Heterojunction Behaves as Optical Synapse with 1000s-of-Seconds Persistent Photoconductivity

2021

For some applications, metal halide perovskite materials have problematically high-ion migration properties. However, that same property can also be exploited as a beneficial feature for certain technologies.

Scientific Achievement

We demonstrate a phototransistor composed of semiconducting carbon nanotubes (CNTs) decorated with perovskite nanocrystals, which show long-lived photoinduced memory effects.

Significance and Impact

Solid-state optoelectronic memory technologies and optical switches could replace electrically stimulated resistive switches in photonic integrated circuits and dynamically configurable neural networks for energy-efficient, brain-inspired (neuromorphic) computing and information processing.

Research Details

  • Constructed a nano-heterojunction from perovskite nanocrystals decorated onto carbon nanotube arrays.
  • Showed, upon light excitation, a dramatic change in photoconductivity for 1000s of seconds after excitation.
  • Proved process to be driven by ion migration and optically written and erased easily with voltage pulses.

DOI: Forthcoming

Related People

Joseph Luther
National Renewable Energy Laboratory

Jeffrey Blackburn
National Renewable Energy Laboratory

Illustration of a photoinduced hole transfer on a perovskite solar cell along with two charts: one showing light measurements and the other showing time measurements.

Phototransistors of (6,5) single-wall CNTs decorated with perovskite nanocrystals were fabricated on pre-patterned silicon chips. Upon illumination, the conductivity between the source and drain electrode rises dramatically and remains elevated for thousands of seconds after the light is turned off. This effect arises from photoinduced ion migration within the perovskite array and opens the door to a variety of new energy-efficient applications such as neuromorphic computing and quantum information processing.