Quantum mechanics

Chemical physics

Materials science

Layer (electronics)

Curse of dimensionality

Crossover

Computer science

Semiconductor

Physical chemistry

Physics

Nanotechnology

Electron mobility

Semiconductor device

Condensed matter physics

Electronics

Artificial intelligence

Chemistry

Electron

Optoelectronics

Machine learning

Nano Letters

Two-dimensional (2D) semiconductors are at the center of an intense research effort aimed at developing the next generation of flexible, transparent, and energy-efficient electronics. In these applications, the carrier mobility, that is the ability of electrons and holes to move rapidly in response to an external voltage, is a critical design parameter. Here, we show that the interlayer coupling between electronic wave functions in 2D semiconductors can be used to drastically alter carrier mobility and dynamics. We demonstrate this concept by performing state-of-the-art ab initio calculations for InSe, a prototypical 2D semiconductor that is attracting considerable attention, because of its exceptionally high electron mobility. We show that the electron mobility of InSe can be increased from 100 cm2 V–1 s–1 to 1000 cm2 V–1 s–1 by exploiting the dimensional crossover of the electronic density of states from two dimensions to three dimensions. By generalizing our results to the broader class of layered materials, we discover that dimensionality plays a universal role in the transport properties of 2D semiconductors.

Dimensional Crossover in the Carrier Mobility of Two-Dimensional Semiconductors: The Case of InSe