Carrier spin dynamics in modulation-doped InAs/GaAs quantum dots
2006 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 100, no 5, 054310- p.Article in journal (Refereed) Published
Photoexcited electron and hole spin relaxation was studied in modulation-doped and undoped InAs/GaAs quantum dots by means of time-resolved photoluminescence. After excitation into the barriers or the wetting layer, the electron spin polarization is preserved during the capture and relaxation in the dots, especially in the p-doped structures, and decays with a characteristic time of about 100 ps. Spin state admixture in combination with electron interaction with acoustic phonons is suggested as the spin relaxation mechanism. Rapid spin polarization decay during carrier relaxation in undoped quantum dots is attributed to electron-optical phonon interaction. For carrier excitation directly into the dots, no significant spin polarization was observed, which points to the mixed nature of hole levels in quantum dots. The hole spin polarization randomizes on a much shorter time scale and is not detected in the experiment.
Place, publisher, year, edition, pages
2006. Vol. 100, no 5, 054310- p.
Electrons, Polarization, Relaxation processes, Semiconducting gallium arsenide, Semiconducting indium compounds, Wetting
IdentifiersURN: urn:nbn:se:kth:diva-5879DOI: 10.1063/1.2337776ISI: 000240602500103ScopusID: 2-s2.0-33748846722OAI: oai:DiVA.org:kth-5879DiVA: diva2:10406
QC 20100902. Uppdaterad från In press till Published (20100902)2006-06-012006-06-012010-09-02Bibliographically approved