Researchers make speedy phase-change memory with carbon nanotubes

The flash memory used in mobile devices today stores bits as charge, which requires high programming voltages and is relatively slow. Industry has been exploring faster, but higher power phase-change materials (PCM) as an alternative. In PCM memory a bit is stored in the resistance of the material, which is switchable.

Pop’s group lowered the power per bit to 100 times less than existing PCM memory by focusing on one simple, yet key factor: size.

Rather than the metal wires standard in industry, the group used carbon nanotubes, tiny tubes only a few nanometers in diameter – 10,000 times smaller than a human hair.

“The energy consumption is essentially scaled with the volume of the memory bit,” said graduate student Feng Xiong, the first author of the paper. “By using nanoscale contacts, we are able to achieve much smaller power consumption.”