| Autor: |
Tinjod, F., Moehl, S., Kheng, K., Gilles, B., Mariette, H. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 1/1/2004, Vol. 95 Issue 1, p102-108, 7p, 1 Chart, 6 Graphs |
| Abstrakt: |
We report the dependence of the growth and the optical properties of self-assembled CdTe/Zn[sub 1-x]Mg[sub x]Te quantum dots on the barrier Mg content x (0<=x<=0.3). Due to the decrease of the lattice mismatch between CdTe and Zn[sub 1-x]Mg[sub x]Te with increasing x, we use a technique for inducing dot formation, based on efficient reduction of the surface energy by deposition of amorphous Te, which is then desorbed. Mg incorporation in the barriers leads to a better heavy-hole confinement along the growth axis, which is manifested in photoluminescence (PL) studies by both an extension of the radiative regime temperature range (up to 150 K for 30% Mg) and a strong increase of the activation energy for the nonradiative recombination. However, the in-plane confinement is less enhanced, which allows observation of interdot carrier transfer with increasing temperature, as evidenced directly by the analysis of PL intensities for different single dots. Our temperature-dependent data (time-resolved and microphotoluminescence) suggest that this transfer consists of a thermally activated process via the two-dimensional wetting-layer states rather than a direct tunneling (hopping) process. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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