2016/02/01 by George Kioseoglou, Γ. Κιοσέογλου, Kioseoglou, George +8 · 2 citations
Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Chalcogenide Semiconductor Thin Films #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Spectroscopy and Quantum Chemical Studies #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.1602.00640
14 pages, 5 figures
arxiv created 2016/02/01 · openalex publication_date 2016/02/01 · arxiv updated 2016/02/02 · openalex created_date 2022/10/07 · openalex updated_date 2026/07/28
Single layers of MoS2 and MoSe2 were optically pumped with circularly polarized light and an appreciable polarization was initialized as the pump energy was varied. The circular polarization of the emitted photoluminescence was monitored as function of the difference between the excitation energy and the A-exciton emission at the K-point of the Brillouin zone. Our results show a threshold of twice the LA phonon energy, specific to the material, above which phonon-assisted intervalley scattering causes depolarization. In both materials this lead to almost complete depolarization within ~100 meV above the threshold energy. We identify the extra kinetic energy of the exciton (independent of whether it is neutral or charged) as the key parameter for presenting a unifying picture of the depolarization process.