Strain effects on the electronic structure of SrTiO3: Toward high electron mobilities

Using the screened hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE) we explore the effects of strain on the energetic ordering and effective mass of the lowest conduction-band states in SrTiO3. We predict that biaxial stress in the (001) or (110) planes results in the lowest-energy conduction-band state having significantly smaller electron mass in the in-plane directions compared to the unstrained SrTiO3, thus suggesting that pseudomorphic growth is a promising route to increasing the electron mobility in epitaxial films. We propose possible substrates that may lead to SrTiO3 films with enhanced electron mobilities, and report deformation potentials that allow accurate prediction of conduction-band splittings for arbitrary strain configurations.