Odnos anomalne transmisije i negativnog gašenja u Braggovom slučaju

The relationship between the anomalous transmission and the negative extintion in the symmetrical Bragg case near the absorption edge is studied in detail. The negative extinction results from the anomalous transmission and takes the largest value when the diffraction is induced only by the imaginary part of the atomic scattering factor near the absorption edge. The appearance of the negative extinction also depends on temperature, which can be used for the identification of the theoretical model for calculating the Debye-Waller factor.Podrobno se razmatra odnos anomalne transmisije i negativnog gašenja za simetričan Braggov slucaj. Negativno gašenje je posljedica anomalne transmisije i najveće je kada je difrakcija uzrokovana samim imaginarnim dijelom atomskog faktora raspršenja u blizini apsorpcijskog ruba. Pojava negativnog gašenja ovisi također o temperaturi, što se može primijeniti za prepoznavanje teorijskog modela pri izračunavanju Debye-Wallerovog faktora

Carrier Dynamics in Submonolayer InGaAs/GaAs Quantum Dots

Carrier dynamics of submonolayer (SML) InGaAs/GaAs quantum dots (QDs) were studied by micro-photoluminecence (MPL), selectively excited photoluminescence (SEPL), and time-resolved photoluminescence (TRPL). MPL and SEPL show the coexistence of localized and delocalized states, and different local phonon modes. TRPL reveal shorter recombination lifetimes and longer capture times for the QDs with higher emission energy. This suggests that the smallest SML QDs are formed by perfectly vertically correlated 2D InAs islands, having the highest In content and the lowest emission energy, while a slight deviation from the perfectly vertical correlation produces larger QDs with lower In content and higher emission energy.Comment: 12 pages, 5 figure