Excitonic terahertz emission from Si at intense interband photoexcitation
| Autor: | A. O. Zakhar'in, A. V. Andrianov, A. G. Petrov |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Condensed Matter::Quantum Gases
010302 applied physics Materials science Photoluminescence Condensed Matter::Other Terahertz radiation Mechanical Engineering Exciton Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics Population inversion 01 natural sciences Photoexcitation Condensed Matter::Materials Science Mechanics of Materials Excited state 0103 physical sciences General Materials Science Atomic physics 010306 general physics Ground state Biexciton |
| Zdroj: | Materials Science and Engineering: B. 263:114892 |
| ISSN: | 0921-5107 |
| Popis: | Terahertz photoluminescence from silicon crystals due to radiative transitions between the energy levels of free excitons has been studied up to intensities of interband photoexcitation significantly exceeding the threshold for the formation of electron-hole liquid droplets. At temperatures above 20 K and a photoexcitation density in excess of 7 W/cm2, the appearance of stimulated intraexciton terahertz radiation was clearly demonstrated. Terahertz gain spectrum was obtained. The gain spectrum indicates that population inversion arises between the highly excited states of excitons and sublevels of the ground state of free excitons, as well as possibly between two-exciton and biexciton states. The performed calculations of the times of energy relaxation of exciton states show the fundamental possibility of the appearance of population inversion between the states of excitons in the process of their energy relaxation. |
| Databáze: | OpenAIRE |
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