| Autor: |
Sˇermuksˇnis, E., Liberis, J., Ramonas, M., Matulionis, A., Leach, J. H., Wu, M., Avrutin, V., Morkoç, H. |
| Předmět: |
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| Zdroj: |
Applied Physics Letters; 7/25/2011, Vol. 99 Issue 4, p043501, 3p, 4 Graphs |
| Abstrakt: |
Fluctuation technique is used to measure hot-phonon lifetime in dual channel GaN-based configuration proposed to support high-power operation at high frequencies. The channel is formed of a composite Al0.1Ga0.9N/GaN structure situated in an Al0.82In0.18N/AlN/Al0.1Ga0.9N/GaN heterostructure. According to capacitance-voltage measurements and simultaneous treatment of Schrödinger-Poisson equations, the mobile electrons in this dual channel configuration form a camelback density profile at elevated hot-electron temperatures. The hot-phonon lifetime was found to depend on the shape of the electron profile rather than solely on its sheet density. The camelback channel with an electron sheet density of 1.8 × 1013 cm-2 demonstrates ultrafast decay of hot phonons at hot-electron temperatures above 600 K: the hot-phonon lifetime is below ∼60 fs in contrast to ∼600 fs at an electron sheet density of 1.2 × 1013 cm-2 obtained in a reference Al0.82In0.18N/AlN/GaN structure at 600 K. The results suggest a suitable method to increase the electron sheet density without the deleterious effect caused by inefficient hot-phonon decay observed in a standard design at similar electron densities. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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