Self-Modulation Doping Effect in the High-Mobility Layered Semiconductor Bi2O2Se

Abstract

Recently an air-stable layered semiconductor Bi2O2Se was discovered to exhibit an ultrahigh mobility in transistors fabricated with its thin layers. In this work, we explored the mechanism that induces the high mobility and distinguishes Bi2O2Se from other semiconductors. We found that the electron donor states lie above the lowest conduction band. Thus, electrons get spontaneously ionized from donor sites (e.g., Se vacancies) without involving the thermal activation, different from the donor ionization in conventional semiconductors. Consequently, the resistance decreases as reducing the temperature as observed in our measurement, which is similar to a metal but contrasts to a usual semiconductor. Furthermore, the electron conduction channels locate spatially away from ionized donor defects (Se vacancies) in different van der Waals layers. Such a spatial separation can strongly suppress the scattering caused by donor sites and subsequently increase the electron mobility, especially at the low temperature. We call this high-mobility mechanism self-modulation doping, i.e. the modulation doping spontaneously happening in a single-phase material without requiring a heterojunction. Our work paves a way to design novel high-mobility semiconductors with layered materials.

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Cited by in corpus (10)

• T-square resistivity without Umklapp scattering in dilute metallic Bi${}_2$O${}_2$Se
• Epitaxial growth and characterization of high quality Bi2O2Se thin films on SrTiO3 substrates by pulsed laser deposition
• Direct visualization of ambipolar Mott transition in cuprate CuO2 planes
• Magnitude and Spatial Distribution Control of the Supercurrent in Bi2O2Se-Based Josephson Junction
• Huge permittivity and premature metallicity in Bi${}_2$O${}_2$Se single crystals
• Gate-tunable h/e-period magnetoresistance oscillations in Bi2O2Se nanowires
• Bi2O2Se nanowires presenting high mobility and strong spin-orbit coupling
• Polar discontinuities and interfacial electronic properties of Bi${}_2$O${}_2$Se on SrTiO${}_3$
• Phonon properties and unconventional heat transfer in quasi-2D $B{i}_2{O}_{2}Se$ crystal
• Enhancing Quasi-Two-Dimensional Electronic Structure in Bi2O2Se via Chlorine Substitution