Femtosecond exciton dynamics and the mott transition in GaN under resonant excitation
We present resonant femtosecond pump-probe reflectance measurements of excitons in high quality wurtzite GaN epilayers for a range of lattice temperatures and various pump intensities. From the density dependence of the excitonic bleaching we find that the Mott density is n(Mott) less than or equal...
| Main Authors: | , , , , , |
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| Format: | Conference item |
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1999
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| _version_ | 1797081894876086272 |
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| author | Hess, S Taylor, R Kyhm, K Ryan, J Beaumont, B Gibart, P |
| author_facet | Hess, S Taylor, R Kyhm, K Ryan, J Beaumont, B Gibart, P |
| author_sort | Hess, S |
| collection | OXFORD |
| description | We present resonant femtosecond pump-probe reflectance measurements of excitons in high quality wurtzite GaN epilayers for a range of lattice temperatures and various pump intensities. From the density dependence of the excitonic bleaching we find that the Mott density is n(Mott) less than or equal to 2.2 x 10(19) cm(-3). At 4 K we find that the exciton dynamics is dominated by trapping at defects via acoustic phonon emission on a timescale of similar to 16 ps. At temperatures above 60 K we observe a much longer relaxation component of similar to 350 to 400 ps, which we ascribe to the radiative recombination of free excitons. |
| first_indexed | 2024-03-07T01:20:32Z |
| format | Conference item |
| id | oxford-uuid:9027a747-f19f-4c24-bf70-a8a582341142 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T01:20:32Z |
| publishDate | 1999 |
| record_format | dspace |
| spelling | oxford-uuid:9027a747-f19f-4c24-bf70-a8a5823411422022-03-26T23:09:41ZFemtosecond exciton dynamics and the mott transition in GaN under resonant excitationConference itemhttp://purl.org/coar/resource_type/c_5794uuid:9027a747-f19f-4c24-bf70-a8a582341142Symplectic Elements at Oxford1999Hess, STaylor, RKyhm, KRyan, JBeaumont, BGibart, PWe present resonant femtosecond pump-probe reflectance measurements of excitons in high quality wurtzite GaN epilayers for a range of lattice temperatures and various pump intensities. From the density dependence of the excitonic bleaching we find that the Mott density is n(Mott) less than or equal to 2.2 x 10(19) cm(-3). At 4 K we find that the exciton dynamics is dominated by trapping at defects via acoustic phonon emission on a timescale of similar to 16 ps. At temperatures above 60 K we observe a much longer relaxation component of similar to 350 to 400 ps, which we ascribe to the radiative recombination of free excitons. |
| spellingShingle | Hess, S Taylor, R Kyhm, K Ryan, J Beaumont, B Gibart, P Femtosecond exciton dynamics and the mott transition in GaN under resonant excitation |
| title | Femtosecond exciton dynamics and the mott transition in GaN under resonant excitation |
| title_full | Femtosecond exciton dynamics and the mott transition in GaN under resonant excitation |
| title_fullStr | Femtosecond exciton dynamics and the mott transition in GaN under resonant excitation |
| title_full_unstemmed | Femtosecond exciton dynamics and the mott transition in GaN under resonant excitation |
| title_short | Femtosecond exciton dynamics and the mott transition in GaN under resonant excitation |
| title_sort | femtosecond exciton dynamics and the mott transition in gan under resonant excitation |
| work_keys_str_mv | AT hesss femtosecondexcitondynamicsandthemotttransitioninganunderresonantexcitation AT taylorr femtosecondexcitondynamicsandthemotttransitioninganunderresonantexcitation AT kyhmk femtosecondexcitondynamicsandthemotttransitioninganunderresonantexcitation AT ryanj femtosecondexcitondynamicsandthemotttransitioninganunderresonantexcitation AT beaumontb femtosecondexcitondynamicsandthemotttransitioninganunderresonantexcitation AT gibartp femtosecondexcitondynamicsandthemotttransitioninganunderresonantexcitation |