Characterization and growth of doped-PbS in situ with Bi 3+ , Cd 2+ and Er 3+ ions by chemical bath

Portillo, M. Chávez; Moreno, O. Portillo; Pérez, R. Gutiérrez; Palomino-Merino, R.; Juárez, H.; Cuapa, Samuel Tehuacanero; Rosas, Efraín Rubio

doi:10.1016/j.mssp.2017.09.012

Cited by 34 publications

(11 citation statements)

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“…In this FTIR spectrum, a strong and sharp absorption band is presented in all the nanocrystals located at 1385 cm −1 , differing only in intensity, which is attributed to asymmetric stretching vibration of the CO 2− 3 anions [4]. As mentioned before, L-tryptophan and CO 2− 3 ion probably generate the overlap of their corresponding bands, although this fact must be justified by theoretical models that we will leave for future reports.…”

Section: Resultsmentioning

confidence: 61%

“…This shift in the diffraction lines can be attributed to lattice strain resulting from structural disorder generated by the doping effect. This shift in reflections is usually typical and is associated with the incorporation into the crystal lattice of the dopant ion [3][4][5]10].…”

Section: Resultsmentioning

confidence: 99%

“…In several reports, doping is performed with positive and/or negative monovalent ions (Li + ) and divalent (Cu 2+ or Se 2− ) and trivalent (In 3+ ) ions, as well as the simultaneous incorporation of Cd 2+ , Bi 3+ , and Er 3+ ions into the crystal lattice of PbS [4], and, in all these reports, a GS decrease due to the effect of the dopant ion can be observed. A GS decrease is expected to lead to enhanced growth of stable nuclei in the initial growth stages, resulting consequently in smaller GS in the PbS-T nanocrystals.…”

Section: Resultsmentioning

confidence: 99%

“…This semiconductor has the advantage of modifying its morphological, structural, optical, and electrical properties by means of systematic doping with different cations and anions. Latest reports of doped-PbS nanocrystals with different monovalent and divalent ions and even with three inorganic ions which have been systematically incorporated in the crystal lattice showed the different reasons for investigating this semiconductor in depth according to the interesting changes observed [3,4]. As it is well-known, this semiconductor has been synthesized using various techniques, such as atomic layer deposition [5], SILAR [6], hydrothermal synthesis [7], hot injection method [8], and chemical bath deposition [9].…”

Section: Introductionmentioning

confidence: 99%

“…E g shifts in the range of the spectral region between~0.4 and 3.5 eV when the GS decreases below the size of the excitonic Bohr radius (~18 nm) due to the quantum confinement effect; this is one of the characteristics worthy of investigation in this material. There are several reports that have shown that in doping systematically with different inorganic ions, it is possible to modify the morphological, structural, optical, and electrical properties [3,4,10]. Some other reports of doping with metalorganic compounds in PbS have shown results that attract attention by charge transfer along with structural and optical changes [11], a phenomenon that establishes the importance of doping with different organic molecules.…”

Section: Introductionmentioning

confidence: 99%

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Influence of L-Tryptophan on Growth and Optical Properties of PbS Nanocrystalline Thin Films

Palomino-Merino

Pérez

Trejo-García

et al. 2018

Journal of Nanomaterials

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The growth through the green chemical bath of PbS doped systematically with the biomolecule L-tryptophan led to growth of hybrid, inorganic-organic, nanocrystalline thin films onto glass slides at T~80°C. The thickness was found in the range of 230-140 nm. Morphological changes were analyzed using atomic force microscopy (AFM). FTIR (Fourier-transform infrared spectroscopy) spectra showed broad absorption bands located at~3450 cm −1 attributed to stretching of the H 2 O molecules and two small absorption bands located at~2285 cm −1 and~2918 cm −1 along with a strong band at~1385 cm −1 assigned to vibration modes corresponding to CO 2− 3 ions. In the patterns of X-ray diffraction (XRD), the cubic phase was identified in all the samples according to the angular positions 2θ~26 08°, 30.13°, 43.08°, 51.91°, 53.60°, 6251°, 68.98°, and 71.15°. Using the Scherrer formula on the XRD patterns, the grain size (GS) was determined; for the undoped sample,~42 nm was found, whereas for the doped samples,~42-22 nm was found. The electronic charge distribution of L-tryptophan was determined using the molecular electrostatic potential (MEP) to understand the decrease on the GS associated with the interaction of π electrons from conjugated rings and amino-acid functional groups. The absorbance spectra in doped films showed excitonic peaks at~1.8-2.1 eV associated to a higher energy of the 1 S h → 1 S h and 1 P h → 1 P e electronic transitions. Through optical absorption, a shift for the band gap energy was observed from~1.4 eV for the undoped sample and~2.1-2.3 eV for the doped films, respectively. Such behaviour is generally associated with the GS decrease and the effect of quantum confinement; a simple model by calculating changes in Gibbs free energy (ΔG°) for growth of nanocrystals is presented.

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Section: Resultsmentioning

confidence: 61%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%