Where there is electricity, heat is generated, which is a major obstacle to shrinking electronic equipment Scientists have now found that nanowires made of an isotope of silicon have 150% better thermal conductivity than ordinary silicon, which may lead to a significant reduction in the temperature of computer chips
In a busy electronic system, the current will produce a lot of heat. If it is allowed to accumulate, it will damage the components. Therefore, cooling technology is also developing rapidly, but as electronic products become smaller and smaller, effective heat dissipation becomes more and more difficult.
In the new study, scientists found a special silicon isotope called "Si-28" (Si-28). The isotope is an atom of a specific element containing different numbers of neutrons. At present, about 92% of silicon exists in the form of "silicon-28", 5% in the form of "silicon-29" (si-29), and the remaining 3% in the form of "silicon-30" (si-30).
In computer chips, these isotopes have the same general electronic functions, but previous studies have found that the "impurities" of si-29 and si-30 interrupt the flow of heat.
In the past, scientists have found that bulk components made of pure "silicon-28" can improve heat conduction by about 10 percent -- it's not bad, but it's not really worth the extra cost. In the new study, the researchers examined the thermal conductivity of nanowires made of pure Si-28.
The team placed a 90 nm wide Si-28 nanowire between two micro heater pads and applied a current to one of them so that the heat generated could flow through the nanowire to the other. Scientists expect the improvement to be about 20 percent -- but to their great surprise, it performs 150 percent better than natural silicon nanowires.
Careful inspection found that a layer of silica was formed on the outside of the nanowires, which effectively smoothed the usually rough surface and made it scatter heat. Internally, due to the lack of other isotopes, heat can pass through the core of nanowires smoothly.
However, there is a major problem - the separation of silicon-28 from other isotopes is still expensive and difficult. However, progress can also be made in this area in the future, especially with some new reasons to do so.
The research was published in the journal Physical Review Letters.
Source: Berkeley Lab