Optical and structural properties of CdS:Pb$^{2+}$ nanocrystals

R. Gutiérrez, O. Portillo, M. Chávez, H. Juárez, M. Pacio, L. Chaltel, M. Zamora, M. Lazcano, E. Rubio, G. Hern, ez.


The goal of this work is to study the effects of doping on structural, morphological and optical properties of CdS thin films as a function of Pb$^{2+}$ concentration. Thus, nanoparticles were synthesized by chemical bath and a thickness decrease of $\sim$575-200 nm range was observed. In Fourier-transform infrared spectroscopy, all the samples showed a sharp stretching mode observed at $\sim$1384 cm$^{-1}$ corresponding to the vibration mode of CO$_3^{-2}$. X-ray diffraction studies show that the size of crystallites is in the $\sim$33-12 nm range. The peaks belonging to primary phase are identified at the $2\theta = 26.5^{\circ}$ and $2\theta = 26.00^{\circ}$, corresponding to CdS and PbS respectively.
Thus, a shift in maximum intensity peak from $2\theta = 26.4^{\circ}$ to 28.2$^{\circ}$ is observed. Likewise peaks at $2\theta = 13.57^{\circ}$, 15.91$^{\circ}$ correspond to lead perchlorate thiourea. The optical, absorption, and transmission properties of the films were determined by UV-vis spectrophotometry, optical energy gap was found to range from 2.1 to 2.4 eV. Raman spectroscopy on doped films showed a shifting of these modes that can be attributed to strain, stress effects, defects, phonon confinement, and variation in phonon relaxation with grain size.


Chemical bath; CdS; cell potential; nanoparticles; coordination complex; doping

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Revista Mexicana de Física

ISSN: 2683-2224 (on line), 0035-001X (print)

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