The use of ultrathin 2D semiconductor materials promises to shrink transistors down to the nanometre scale. However, to achieve a substantial increase in the number of these transistors that can fit on a chip, it is necessary to scale down the metallic contacts that link them to external circuitry. So far, it has not been clear how small these contacts can be made before device performance is compromised. Writing in Nature, Yang et al.1 report a direct measurement of the minimum contact size needed to generate current efficiently in an atomically thin (2D) semiconductor. Their result, 2–3 nanometres, is a promising sign that the contacts for 2D transistors can be scaled down along with the devices themselves.
Competing Interests
The author declares no competing interests.
