▎ 摘　　要

Thin layers of the semiconductor silicon are omnipresent in all electronic devices. Ongoing, exponential improvement in size, performance, and cost of a single transistor is predicted to face serious challenges in the near feature. With the era of "postsilicon electronics" on the horizon, researchers are racing to address issues of material security, less energy-intensive manufacturing, and design of device properties. The chemistry of carbon and nitrogen (C, N) provides an attractive avenue toward the modular design of new 2D materials "beyond silicon and graphene."