Influence of L-Tryptophan on Growth and Optical Properties of PbS Nanocrystalline Thin Films
Joint Authors
Palomino-Merino, R.
Rubio-Rosas, E.
Moreno-Rodríguez, Albino
Gutiérrez Pérez, R.
Trejo García, P.
Chaltel Lima, L.
Portillo Moreno, O.
Araiza García, M. E.
Source
Issue
Vol. 2018, Issue 2018 (31 Dec. 2018), pp.1-15, 15 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2018-07-05
Country of Publication
Egypt
No. of Pages
15
Main Subjects
Abstract EN
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 H2O 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 CO32− 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 1Sh → 1Sh and 1Ph → 1Pe 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.
American Psychological Association (APA)
Palomino-Merino, R.& Gutiérrez Pérez, R.& Trejo García, P.& Chaltel Lima, L.& Portillo Moreno, O.& Araiza García, M. E.…[et al.]. 2018. Influence of L-Tryptophan on Growth and Optical Properties of PbS Nanocrystalline Thin Films. Journal of Nanomaterials،Vol. 2018, no. 2018, pp.1-15.
https://search.emarefa.net/detail/BIM-1194007
Modern Language Association (MLA)
Palomino-Merino, R.…[et al.]. Influence of L-Tryptophan on Growth and Optical Properties of PbS Nanocrystalline Thin Films. Journal of Nanomaterials No. 2018 (2018), pp.1-15.
https://search.emarefa.net/detail/BIM-1194007
American Medical Association (AMA)
Palomino-Merino, R.& Gutiérrez Pérez, R.& Trejo García, P.& Chaltel Lima, L.& Portillo Moreno, O.& Araiza García, M. E.…[et al.]. Influence of L-Tryptophan on Growth and Optical Properties of PbS Nanocrystalline Thin Films. Journal of Nanomaterials. 2018. Vol. 2018, no. 2018, pp.1-15.
https://search.emarefa.net/detail/BIM-1194007
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1194007