Temperature dependence of trap luminescence of CdS doped glasses

Identification of surface states in PbS quantum dots by temperature dependent photoluminescence

“…In all the transition bands, the peak intensity decreases monotonically, however in case of the 1.67 eV band, it is seen that the integrated intensity has either tends to saturate or shows a maximum at a specific temperature, which is more prominent in the Pb:S::10:1 sample. This kind of anomalous behavior was also observed in other nanoparticle systems, which was attributed to the variation of size in the nanoparticle distribution [14][15][16]. This was considered to be the result of competition between radiative and non-radiative (hopping) transitions.…”

“…This was considered to be the result of competition between radiative and non-radiative (hopping) transitions. In the literature, this hopping mechanism is modeled by a kind of activation energy (E esc or E hopp ), which depends on the relative size distribution, which in turn causes the peak behavior in PL intensity at a particular temperature [14][15][16]. At present, we have not modeled the spectra.…”

CdS : SiO2 nanocomposite as a luminescence-based wide range temperature sensor

“…1. Thus, absence of band edge emission indicates that the dominating process in present study is surface state recombination and may be attributed to very narrow distribution with large number of small nanocrystals 30 . Dib et al suggested that the band-edge PL band (~ 515 nm for bulk CdS) appears due to the direct excitonic recombination in quantum dots (QDs) having a diameter larger than 3 nm.…”

Simple preparation of a cadmium selenide–montmorillonite hybrid

“…4, inset) revealed only a weak emission peak due to the band-edge emission at 523 nm with a FWHM of 89 nm. By comparison, the FWHM of the emission band of CdSe-HDTMAmontmorillonite was narrower and the PL intensity was two times higher than those of CdSe-HDTMA, indicating the uniform shape, size, and size distribution of CdSe formed in the interlayer space of montmorillonite [10,27,28]. The blue shift of the near band-edge emission of CdSe-HDTMA-montmorillonite (507 nm) with respect to the band-edge emission of CdSe-HDTMA (523 nm) was thought to originate from the effects of quantum confinement and/or the rigid nature of the silicate layer [29], and the trap emission of the modified CdSe in montmorillonite was arisen from the surface defects and/or site-substituted impurities of the nanoparticles, which were assumed to be caused by the clay mineral.…”

“…4 together with those of CdSe-HDTMA. The intensities of the emission bands of both samples were gradually quenched as the temperature increased, because the competitive nonradiation process occurring in CdSe particles became effective [12,27]. It has been reported that the red shift of the emission peak for a semiconductor with increasing temperature involved shrinking of the energy band gap and exiton-phonon coupling [30].…”