نتایج جستجو برای: Exciton
تعداد نتایج: 7737 فیلتر نتایج به سال:
We consider the interaction of quantum light with an ideal semiconductor microcavity. We investigate photon statistics in different conditions and the presence of detuning and exciton-exciton interaction. We show that in the resonant interaction and absence of the exciton-exciton interaction, the state of the whole system can be considered as coherent state. According to our results, it turns...
چکیده : در این پایان نامه، لایه های نازک نمونه های zno و zno:mn در غلظت های متفاوت mn با استفاده از روش سل-ژل بر روی بسترهای شیشه ای ساخته شدند. خواص اپتیکی با استفاده از بیضی نگار (ellipsometer) مورد مطالعه قرار گرفتند. نتایج حاصل از بیضی نگاری، با استفاده از مدل tauc- lorentz فیت شدند و در نهایت تغییرات شدت برهمکنش exciton-phononبرای نمونه های آلایش شده مورد مطالعه قرار گرفت. بررسی های ما نش...
Thermal variation of PL peak energy of undoped nitride semiconductor quantum well shows a successive red-blue-red shifted emission (S-shaped behavior). This behavior has been attributed to the localization of excitons at the energy minima induced by the potential fluctuations in the quantum well structure and/or interface roughness. The S-shaped behavior of PL peak position, the thermal variati...
We systematically investigate the exciton dynamics in monolayered, bilayered, and trilayered WS2 two-dimensional (2D) crystals by time-resolved photoluminescence (TRPL) spectroscopy. The exciton lifetime when free of exciton annihilation was determined to be 806 ± 37 ps, 401 ± 25 ps, and 332 ± 19 ps for WS2 monolayer, bilayer, and trilayer, respectively. By measuring the fluorescence quantum yi...
Monolayer MoS2 is a direct-gap two-dimensional semiconductor that exhibits strong electron-hole interactions, leading to the formation of stable excitons and trions. Here we report the existence of efficient exciton-exciton annihilation, a four-body interaction, in this material. Exciton-exciton annihilation was identified experimentally in ultrafast transient absorption measurements through th...
Exciton-polaritons are mixed light-matter quasiparticles. We have developed a statistical model describing stochastic exciton-photon transitions within a condensate of exciton polaritons. We show that the exciton-photon correlator depends on the rate of incoherent exciton-photon transformations in the condensate. We discuss implications of this effect for the quantum statistics of photons emitt...
The two-exciton manifold of a double-wall cylindrical molecular aggregate is studied using a coherent third order optical technique. Experiments reveal the anharmonic character of the exciton bands. Atomistic simulations of the exciton-exciton scattering show that the excitons can be treated as weakly coupled hard-core bosons. The weak coupling stems from the extended exciton delocalization mad...
We generalize our recent work on the optical bistability of thin films of molecular aggregates [J. A. Klugkist et al., J. Chem. Phys. 127, 164705 (2007)] by accounting for the optical transitions from the one-exciton manifold to the two-exciton manifold as well as the exciton-exciton annihilation of the two-exciton states via a high-lying molecular vibronic term. We also include the relaxation ...
Bound electron–hole pairs—excitons—are Bose particles with small mass. Exciton Bose–Einstein condensation is expected to occur at a few degrees Kelvin—a temperature many orders of magnitude higher than for atoms. Experimentally, an exciton temperature well below 1 K is achieved in coupled quantum well (CQW) semiconductor nanostructures. In this contribution, we review briefly experiments that s...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید