Temperature dependent effects on luminescence polarization and recombination lifetime in serpentine superlattice quantum wire arrays
✍ Scribed by H. Weman; C.I. Harris; J.P. Bergman; M.S. Miller; J.C. Yi; J.L. Merz
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 196 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0749-6036
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✦ Synopsis
We have measured photoluminescence excitation (PLE) spectra and radiative lifetimes as functions of temperature for serpentine superlattice quantum-wire arrays. The (Al, Ga)As arrays have lateral periods near (10 \mathrm{~nm}), and lateral confining potentials of (120 \mathrm{meV}) in the conduction band. At low temperature the excitons are strongly localized within potential fluctuations along the wires. The radiative lifetime of these localized states is (340 \mathrm{ps}) at (2 \mathrm{~K}). The degree of exciton localization decreases with increasing temperature, from which we estimate the strongly-localizing potential fluctuations to be approximately (10 \mathrm{meV}) deep. Above (80 \mathrm{~K}) the excitons have sufficient thermal energy for motion along the wires. The radiative lifetimes increase with temperature, to (20 \mathrm{~ns}) for free carriers at (325 \mathrm{~K}). The lateral potential barriers inhibit diffusion to non-radiative recombination sites.