Influence of interface potential on the effective mass in Ge nanostructures

Journal Article · Tue Apr 21 04:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4918549· OSTI ID:22402873

Cosentino, S.; Terrasi, A.; Mirabella, S. ^[1]; Lockwood, D. J. ^[2]; Costa Filho, R. N. ^[3]

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1. MATIS IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy)
2. Measurement Science and Standards, National Research Council, Ottawa, Ontario K1A 0R6 (Canada)
3. Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Campus do Pici, 60455-760 Fortaleza, Ceará (Brazil)

The role of the interface potential on the effective mass of charge carriers is elucidated in this work. We develop a new theoretical formalism using a spatially dependent effective mass that is related to the magnitude of the interface potential. Using this formalism, we studied Ge quantum dots (QDs) formed by plasma enhanced chemical vapour deposition (PECVD) and co-sputtering (sputter). These samples allowed us to isolate important consequences arising from differences in the interface potential. We found that for a higher interface potential, as in the case of PECVD QDs, there is a larger reduction in the effective mass, which increases the confinement energy with respect to the sputter sample. We further understood the action of O interface states by comparing our results with Ge QDs grown by molecular beam epitaxy. It is found that the O states can suppress the influence of the interface potential. From our theoretical formalism, we determine the length scale over which the interface potential influences the effective mass.

• OSTI ID: 22402873
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 15 Vol. 117; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGE CARRIERS
CHEMICAL VAPOR DEPOSITION
COMPARATIVE EVALUATIONS
CONFINEMENT
EFFECTIVE MASS
INTERFACES
MOLECULAR BEAM EPITAXY
PLASMA
POTENTIALS
QUANTUM DOTS
SPUTTERING