High-energy electron irradiation effects onCdS1−xSexquantum dots in borosilicate glass

Optical Absorption Processes in CdSe Nanocrystals Embedded in Silicate Glass and Organic Polymer Matrices Under 7-MeV Electron Irradiation

“…This is generally consistent with the behaviour of the absorption spectra of the host media without nanocrystals under electron irradiation. While for electronirradiated ( = 10 14 -10 15 cm −2 ) borosilicate glass we observed a noticeable additional absorption, described with three bands with the maxima at 1.9, 3.1, and 4.6 eV, 50 increasing with the irradiation dose, for gelatine at = 10 14 cm −2 we found no changes with respect to the absorption of the non-irradiated sample.…”

“…However, such studies have been reported for X-ray irradiated CdS nanocrystals in silicate glass 47 48 as well as glass-embedded CdS 1−x Se x quantum dots irradiated with both X-rays 49 and high-energy electrons 50 where irradiation-induced transformations of the absorption spectra were explained by the nanocrystal ionization. Therefore, it would be interesting to see whether such effect occurs also for CdSe and, moreover, how this effect depends on the type of the dielectric matrix hosting the CdSe nanocrystals.…”

Thermal treatment-dependent chemical composition of ternary CdS1−xSex nanocrystals grown in borosilicate glass

“…5). Even though the estimation of the average nanocrystal size from transmission electron microscopy is preferred compared with its evaluation from the optical absorption spectra, the latter can still be effectively used in the case that the relevant systematic errors are correctly taken into account [3,5,12,14,28]. In effective mass approximation [32] for the glass-embedded nanocrystals and considering the strong confinement regime (the average nanocrystal radius is smaller than the exciton Bohr radius) the energy of the first confinement-related absorption maximum is given by…”

“…The near-spherical shape of thus grown nanocrystals is evidenced by transmission electron microscopy (TEM) [1][2][3]9]. Their average size can be evaluated from TEM [1][2][3]9], small-angle X-ray scattering [5,9,10], low-frequency Raman scattering [10,11], and optical absorption [7,8,[12][13][14] and is known to increase with the thermal treatment duration and/or temperature.…”

Phonon spectra of quaternary Cd1–yZny S1–xSex semiconductor nanocrystals grown in a glass matrix

“…The observed LO peak frequencies correspond to the average NC composition over the NCs involved in the scattering. The asymmetric shape of the LO phonon bands in Cd 1-y Zn y S 1-x Se x NCs is, similarly to CdS 1-x Se x [4,[6][7][8], is explained by a marked contribution from surface phonons in NCs due to the high surface-to-volume ratio as well as (to a less extent) by nonzero-wavevector LO phonons participating in the Raman scattering due to the confinementrelated selection rules relaxation in the NCs.…”