Rudra, SouravChemistry and Physics of Materials Unit andInternational Centre for Materials Science, Jawaharlal NehruCentre for Advanced Scientific Research, Bangalore 560064,India
Author
Rao, DheemahiChemistry and Physics of Materials Unitand International Centre for Materials Science, JawaharlalNehru Centre for Advanced Scientific Research, Bangalore560064, India
Saha, BivasChemistry and Physics of Materials Unit,International Centre for Materials Science, and School ofAdvanced Materials (SAMat), Jawaharlal Nehru Centre forAdvanced Scientific Research, Bangalore 560064, India
Author
Abstract
Electron mobility in nitride semiconductors is limited by electron–phonon, defect, grain-boundary, and dislocation scatterings. Scandium nitride (ScN), an emerging rocksalt indirect bandgap semiconductor, exhibits varying electron mobilities depending on growth conditions. Since achieving high mobility is crucial for ScN’s device applications, a microscopic understanding of different scattering mechanisms is extremely important. Utilizing the ab initio Boltzmann transport formalism and experimental measurements, here we show the hierarchy of various scattering processes in restricting the electron mobility of ScN. Calculations unveil that though Fröhlich interactions set an intrinsic upper bound for ScN’s electron mobility of ∼524 cm2/V·s at room temperature, ionized-impurity and grain-boundary scatterings significantly reduce mobility. The experimental temperature dependence of mobilities is captured well considering both nitrogen-vacancy and oxygen-substitutional impurities with appropriate ratios, and room-temperature doping dependency agrees well with the empirical Caughey–Thomas model. Furthermore, we suggest modulation doping and polar-discontinuity doping to reduce ionized-impurity scattering in achieving a high-mobility ScN for device applications.
Rudra, S., Rao, D., Poncé, S., & Saha, B. (2024). Dominant Scattering Mechanisms in Limiting the Electron Mobility of Scandium Nitride. Nano Letters : a journal dedicated to nanoscience and nanotechnology, 24(37), 11529-11536. https://doi.org/10.1021/acs.nanolett.4c02920 (Original work published 2024)