Evolution of CdS:Mn nanoparticle properties caused by pH of colloid solution and ultrasound irradiation

Abstract

The effects of pH value and precursors concentrations in the growth solution as well as of ultrasound irradiation on the properties of CdS:Mn nanoparticles in PVA matrix are studied. Analysis of the photoluminescence spectra indicates that the increase of the pH value in the growth solution leads to the increase of the density of surface electron states that participate in radiative transitions and to the enlargement of CdS:Mn nanoparticles. We discuss a stabilization of the sizes of CdS:Mn nanoparticles at pH=6 and change of nanoparticle size with decreasing pH value at elevated concentrations of ions HS‐. It is shown that in the ultrasound‐treated samples the size of the particles does not depend on pH value. The effects of ultrasound result primarily from acoustic cavitation. It is demonstrated that the action of two external factors (the value of the medium pH and ultrasound treatment) on the characteristics of nanoparticles is correlated. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Mass Transfer Between Clusters Under Ostwald’s Ripening

“…by the Wagner and by the diffusion ones. Within the framework of this model, the size distribution function of clusters is described by the generalized Lifshitz-Slyozov-Wagner distribution (alloys, nanocomposites as nc CdS /polimer (Savchuk et al, 2010a(Savchuk et al, , 2010b(Savchuk et al, , 2010c or the generalized Chakraverty-Wagner distribution (island films, heterostructures with quantum dots, etc.) If in the resulting flow j the component iV jj << , it can lead to new mechanism of cluster growth under dislocation-matrix or dislocation-surface diffusion, for the each of which the specific size distribution function and the corresponding temporal dependences of r and g r are intrinsic.…”

Structural, optical and photoconductivity characteristics of manganese doped cadmium sulfide nanoparticles synthesized by co-precipitation method

“…Un-doped as well as Mn-doped CdS NPs are synthesized by co-precipitation method, sonochemical method, sol-gel method and reveres micelles method, etc. [14][15][16][17][18][19][20]. Co-precipitation method is simple, inexpensive and high yield producing method.…”

“…Doped II-VI semiconductor materials with transition metal ions (Cu, Fe, Co, Ag and Mn) have attracted researchers and scientific communities as their incorporation leads to tailored structural, optical and luminescence properties [10][11][12]. Mn-doped CdS NPs have got much attention due to modified structural, electrical and luminescence properties [13][14][15][16][17][18][19]. Un-doped as well as Mn-doped CdS NPs are synthesized by co-precipitation method, sonochemical method, sol-gel method and reveres micelles method, etc.…”

Carbon nanoparticle ionic liquid hybrids and their photoluminescence properties

“…3c and d, respectively, from which we can see that the emission spectra also show excitation dependent feature. The above pH-dependent PL phenomena may be resulted from the density of surface electron localized states that participate in the radiative transitions increases by the adsorption of OH À ions on the surface of CNPIL [16].…”