| Autor: |
Zhou, Qiaoying, Chen, Jiayu, Pattada, B., Manasreh, M. O., Xiu, Faxian, Puntigan, Steve, He, L., Ramaiah, K. S., Morkoç, Hadis |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 6/15/2003, Vol. 93 Issue 12, p10140, 3p, 1 Chart, 2 Graphs |
| Abstrakt: |
Intersubband transitions in Si-doped molecular beam epitaxy grown GaN/AlGaN multiple quantum wells on c-plane sapphire were investigated using the Fourier-transform infrared optical absorption technique. Several GaN quantum well samples were grown with either AlGaN bulk or GaN/AlGaN short period superlattice barriers. The measurements were made in a waveguide configuration utilizing a facet polished at 45° to the c plane. The integrated area of the intersubband transitions in several waveguides cut from different location of the wafer was measured, from which we estimated the two-dimensional electron gas density (σ). The measured values of σ are about two orders of magnitude larger than the Si doping level of ∼8 × 10[SUP17]cm[SUP-3], which is consistent with the polarization effects, particularly considering the large number of GaN/AlGaN interfaces. The internal quantum efficiency of the intersubband transitions was estimated to be on the order of 40% for samples with superlattice barriers. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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