Isotope effects on phonon properties and transport have been predicted and observed for decades. However, despite the crucial impact of electron-phonon interactions, the effect of isotopes on electron transport remains largely unexplored. Here, by using first-principles calculations, we theoretically predict that the electron mobility of lithium hydride (LiH) can increase by up to ∼100% as ${}^3\mathrm{H}$ is replaced with ${}^1\mathrm{H}$. This remarkable phenomenon is primarily attributed to the isotope engineering of the Fröhlich interaction by the mass-induced line shift of the longitudinal optical (LO) phonons. Notably, the isotope-dependent absorption of LO phonons dominates while the isotope-insensitive emission process is mostly suppressed due to energy conservation. We further propose general guidelines for evaluating isotope effects on carrier transport in different materials.

Close

PrevNext

View figure in article

• Carrier dynamics
• Electrical conductivity
• Electron-phonon coupling
• Electronic structure
• First-principles calculations
• Isotope effect
• Optical phonons