House missions, similar to NASA’s Orion that can take astronauts to Mars, are pushing the boundaries of human exploration. However throughout their transit, spacecrafts encounter a steady stream of damaging cosmic radiation, which might hurt and even destroy onboard electronics. To increase future missions, researchers reporting in ACS Nano present that transistors and circuits with carbon nanotubes may be configured to take care of their electrical properties and reminiscence after being bombarded by excessive quantities of radiation.
The lifetime and distance of deep area missions are at present restricted by the power effectivity and robustness of the know-how driving them. For instance, harsh radiation in area can injury electronics and trigger knowledge glitches, and even make computer systems break down fully.
One risk is to incorporate carbon nanotubes in extensively used digital parts, similar to field-effect transistors. These single-atom-thick tubes are anticipated to make transistors extra power environment friendly in comparison with extra run-of-the-mill silicon-based variations. In precept, the ultra-small measurement of the nanotubes must also assist scale back the consequences that radiation would have when putting reminiscence chips containing these supplies. Nevertheless, the radiation tolerance for carbon nanotube field-effect transistors has not been extensively studied. So, Pritpal Kanhaiya, Max Shulaker and colleagues needed to see if they may engineer this sort of field-effect transistor to face up to excessive ranges of radiation, and construct reminiscence chips based mostly on these transistors.
To do that, the researchers deposited carbon nanotubes on a silicon wafer because the semiconducting layer in field-effect transistors. Then, they examined completely different transistor configurations with varied ranges of defending, consisting of skinny layers of hafnium oxide and titanium and platinum steel, across the semiconducting layer.
The workforce discovered that inserting shields each above and beneath the carbon nanotubes protected the transistor’s electrical properties in opposition to incoming radiation as much as 10 Mrad — a stage a lot increased than most silicon-based radiation-tolerant electronics can deal with. When a protect was solely positioned beneath the carbon nanotubes, they had been protected as much as 2 Mrad, which is similar to industrial silicon-based radiation-tolerant electronics.
Lastly, to attain a stability between fabrication simplicity and radiation robustness, the workforce constructed static random-access reminiscence (SRAM) chips with the underside protect model of the field-effect transistors. Simply as with experiments carried out on the transistors, these reminiscence chips had the same X-ray radiation threshold as silicon-based SRAM units.
These outcomes point out that carbon nanotube field-effect transistors, particularly double-shielded ones, may very well be a promising addition to next-generation electronics for area exploration, the researchers say.
Reference: “Carbon Nanotubes for Radiation-Tolerant Electronics” by Pritpal S. Kanhaiya, Andrew Yu, Richard Netzer, William Kemp, Derek Doyle and Max M. Shulaker, 27 October 2021, ACS Nano.
The authors acknowledge funding from the U.S. Air Power Analysis Laboratory and Analog Units, Inc.