Investigation of high density two-dimensional electron gas in Zn-polar BeMgZnO/ZnO heterostructures
| Autor: | Kai Ding, Vitaliy Avrutin, Ümit Özgür, Hadis Morkoç, M. B. Ullah |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Physics and Astronomy (miscellaneous) Condensed matter physics Phonon Resonance Heterojunction 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Piezoelectricity Electrical resistivity and conductivity 0103 physical sciences 0210 nano-technology Fermi gas Ternary operation Molecular beam epitaxy |
| Zdroj: | Applied Physics Letters. 111:182101 |
| ISSN: | 1077-3118 0003-6951 |
| Popis: | Zn-polar BeMgZnO/ZnO heterostructures grown by molecular beam epitaxy on high resistivity GaN templates producing high-density two-dimensional electron gas (2DEG) are investigated. This is motivated by the need to reach plasmon-longitudinal optical (LO) phonon resonance for attaining minimum LO phonon lifetime. Achievement of high 2DEG concentration in MgZnO/ZnO heterostructures requires growth of the MgZnO barrier at relatively low temperatures, which compromises the ternary quality that in turn hinders potential field effect transistor performance. When this ternary is alloyed further with BeO, the sign of strain in the BeMgZnO barrier on ZnO switches from compressive to tensile, making the piezoelectric and spontaneous polarizations to be additive in the BeMgZnO/ZnO heterostructures much like the Ga-polar AlGaN/GaN heterostructures. As a result, a 2DEG concentration of 1.2 × 1013 cm−2 is achieved in the Be0.03Mg0.41Zn0.56O/ZnO heterostructure. For comparison, a 2DEG concentration of 7.7 × 1012 cm−2 req... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|