Transformation of porous doped silica xerogels into multicomponent bulk amorphous monoliths with interesting optical properties

In Situ Assembly of CuxS Quantum-Dots into Thin Film: A Highly Conductive P-Type Transparent Film

“…The optical bandgap ( Eg ) is primarily determined to be ∼2.46 eV by extrapolating the linear part of the curve to the energy axis in the inset of Figure . The bandgap blue-shift is evidently observed for the QD Cu x S film compared with the fundamental bandgaps of copper sulfide (1.2∼2 eV) . Since the QD size of the Cu x S film is smaller than or comparable to the excitonic Bohr radius of Cu x S nanocrystals, it is plausible that the holes and electrons in the Cu x S film will experience a strong confinement with a characteristic reduced mass and a Columbic interaction, and therefore resulting in the optical absorption blue-shift according to the model of the effective-mass approximation (EMA) …”

Optical Features of the Silica Sol–Gel Derived Glasses Doped with Copper Selenide Nanoparticles

“…They had very low light absorption in this range, hence no special subtraction procedure was done for the spectra presented. XRD data evidenced no any new solid phase in them besides typical pattern of the amorphous silica [28]). Characteristics of the samples are collected in Table 1.…”

“…As the whole, XRD pattern of these sol-gel silica glasses doped with copper selenide nanoparticles (Fig. 1 proper analysis deriving atomic pair distribution function may be applied to evaluate more information on its structure [28], however, this is out the framework of the present paper. A series of diffraction peaks due to the Bragg scattering at copper selenide particles enter the range of more 2 values that fortunately provide the feasibility to establish the presence of Cu 2-x Se nanoparticles.…”

Sol–gel silica thin films with copper selenide

“…It was modified to incorporate copper chalcogenides [8,9] and adjusted to attain the production of good quality films of appropriate thickness, 100-500 nm. A synthesis of glasses of similar composition has been also developed [10,11] including the steps of close chemistry, however, the films admit the lower annealing temperatures since thin silica is easier transformable into the homogeneous coating than bulk sol-gel products.…”