R. Yoga Indra Eniya¹, K. Vijayakumar², B. Vigneashwari^3,*

Chalcogenide Letters, Vol.22, No.11, pp. 971-985, 2025, DOI:10.15251/CL.2025.2211.971

Abstract Nanocrystals (~16 nm) of semiconducting lead sulphide (PbS) were synthesized using the coprecipitation method, which was characterized for phase and compositional purity. These ultrafine particles of PbS exhibited quantum confinement characteristics, which were revealed by blue-shifting in optical absorption using UV-DRS analysis. These QDs of PbS were driven under the influence of the applied electric field using monodispersed colloidal suspension on the Indium-Tin-Oxide (ITO) substrate using the electrophoretic deposition technique (EPD). The formation of self-organized arrays of PbS quantum dots (QDs) and their stacked assemblies was achieved through EPD. Interestingly, neither complexing agents nor templates More >

Lekaa K. Abdul Karem¹, Badriah Saad Al-Farhan², Ghada M. G. Eldin³, Samir Kamel⁴, Ahmed M. Khalil^5,*

Journal of Renewable Materials, Vol.13, No.7, pp. 1459-1473, 2025, DOI:10.32604/jrm.2025.02025-0046 - 22 July 2025

Abstract In this study, the casting process is used to fabricate modified polyvinyl alcohol (PVA), starch (S), and carboxymethyl cellulose (CMC) polymer blend films (PVA/S/CMC) loaded with various concentrations of iron-doped carbon quantum dots (Fe-CQDs) and denoted as (PVA/S/CMC@Fe-CQDs). A one-step microwave strategy was employed as a facile method to prepare Fe-CQDs. Through a series of characterization techniques, fourier-transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM) have been used to show the successful integration of Fe-CQDs into the PVA/S/CMC matrix. Loading the synthesized Fe-CQDs to the polymeric matrix significantly enhanced the… More > Graphic Abstract

M. I. Ahamed^a,*, T. Ayyasamy^b, N. Prathap^a, S. Ahamed^c

Chalcogenide Letters, Vol.21, No.3, pp. 285-291, 2024, DOI:10.15251/CL.2024.213.285 - 20 January 2026

Abstract In recent times, zero-dimensional materials have gained importance from a fundamental and technological perspective. Lead selenium sulphide (PbSeS) is a potential candidate for finding interest in its zero-dimensional form among many compound semiconductors. Hence, in this communication, we explored the impact of quantum confinement effects on the energy band gap and wavelength of PbSeS semiconductor nanocrystals (Quantum dots) using cohesive energy and hyperbolic band models (HBM). Experimental data, such as scanning electron microscopy, UV-Vis-NIR, and PL spectroscopies were used to determine the size of nanoparticles and wavelength. PbSeS nanocrystals were also prepared by one-pot synthesis. More >

S. N. Yasinova^a,*, S. I. Mekhtiyeva^b, M. H. Huseynaliyev^a, R. I. Alekberov^b

Chalcogenide Letters, Vol.21, No.5, pp. 377-383, 2024, DOI:10.15251/CL.2024.215.377

Abstract Structural properties of PbSe, PbS and PbS_0.5Se_0.5 thin films and mechanisms of combinational scattering of light from phonons were studied by X-ray diffraction and Raman spectroscopy methods. The results of X-ray diffraction show that the crystallite sizes found in the thin layers of the studied substances are in the order of nanometers and vary in the interval d~10.7 ÷ 30.8 nm. It was determined that the scattering bands of the PbSe_0.5S_0.5 sample with large nanoparticle sizes shift to the region of large wave numbers compared to the scattering bands observed in the region of low wave More >

Prabhakar Misra^1,*, Hawazin Alghamdi¹, Raul Garcia-Sanchez¹, Wyatt Mitchell², Allison Powell³, Nikhil Vohra⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.31, No.4, pp. 1-1, 2024, DOI:10.32604/icces.2024.013296

Abstract Semiconducting quantum dots (Q-dots) with strain-tunable electronic properties are good contenders for quantum computing devices, as they hold promise to exhibit a high level of photon entanglement. The optical and electronic properties of Q-dots vary with their size, shape, and makeup. An assortment of Q-dots has been studied, including ZnO, ZnS, CdSe and perovskites [1]. We have employed both Raman spectroscopy (to precisely determine their vibrational frequencies) and UV-VIS spectroscopy (to determine accurately their band gap energies). The electronic band structure and density of states of the ZnO and ZnS Q-dots have been investigated under More >

A. Kafel^*, S. N. Turki Al-Rashid

Chalcogenide Letters, Vol.20, No.6, pp. 423-429, 2023, DOI:10.15251/CL.2023.206.423

Abstract The study of confined quantum systems exhibit distinct behavior compared to that in bulk solids. This enables the design of materials with tunable chemical, physical, electrical and optical properties. In this paper, the effect of quantum confinement energy on the optical properties (gap energy, refractive index) of semiconductors gallium nitrate (GaN) and zinc sulfide (ZnS) is studied. The study is done using the MATLAB computer program (20a). This software is based on the Brus model and the particle in-a-box model. The results indicate that the optical properties depend on the quantum confinement energy, with an More >

Shyamalima Sharma, Pronob Gogoi, Bhaskar Jyoti Saikia, Swapan K. Dolui^*

Journal of Renewable Materials, Vol.4, No.2, pp. 158-162, 2016, DOI:10.7569/JRM.2015.634116

Abstract Cadmium sulfi de (CdS) quantum dots (QDs) were synthesized by a standard hydrothermal method with simultaneous desulfurization of kerosene oil. Sulfur containing kerosene oil was treated with cadmium chloride (CdCl2) in the presence of sodium hydroxide (NaOH) at 120 °C for 1.5 to 5 h. CdS was formed and sulfur content of oil gradually decreased. Thus, desulfurization of the oil occurred with the formation of the CdS QDs. The concentration of sulfur decreased to a minimum of 0.055% after 5 h of the reaction. In addition, the particle size of QDs increased from 5.4 nm More >

Che-Wun Hong^1,2, Wei-Hui Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.3, pp. 211-228, 2011, DOI:10.3970/cmes.2011.072.211

Abstract This paper intends to use semiconductor quantum dots (cadmium sulphide- CdS) and/or biological pigments (chlorophyll-a derivatives) to replace those expensive ruthenium (Ru) dyes in photoelectrochemical solar cells. Based on the computational quantum chemistry, the molecular structures of (CdS)_n (n=1 ~ 22) clusters and chlorophyll-a derivatives (chlorin-H₃⁺ and chlorin-H₁₇⁺) are configured and optimized. Density functional theory (DFT) of the first principles calculations, which chose B3LYP (Becke 3-parameter Lee-Yang-Parr) and PBE (Perdew-Burke- Ernzerhof) exchange correlation functionals, is employed. Photoelectric properties, such as: molecular orbital, density of state (DOS), highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) and More >

Gerhard Klimeck^1,2, Fabiano Oyafuso², Timothy B. Boykin³, R. Chris Bowen², Paul von Allmen⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.5, pp. 601-642, 2002, DOI:10.3970/cmes.2002.003.601

Abstract Material layers with a thickness of a few nanometers are common-place in today's semiconductor devices. Before long, device fabrication methods will reach a point at which the other two device dimensions are scaled down to few tens of nanometers. The total atom count in such deca-nano devices is reduced to a few million. Only a small finite number of "free'' electrons will operate such nano-scale devices due to quantized electron energies and electron charge. This work demonstrates that the simulation of electronic structure and electron transport on these length scales must not only be fundamentally… More >

Philippe Matagne¹, Jean-Pierre Leburton², Jacques Destine, Guy Cantraine³

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.1, pp. 1-10, 2000, DOI:10.3970/cmes.2000.001.001

Abstract We investigate the quantum mechanical properties and single-electron charging effects in vertical semiconductor quantum dots by solving the Schrödinger and Poisson (SP) equations, self-consistently. We use the finite element method (FEM), specifically the Bubnov-Galerkin technique to discretize the SP equations. Owing to the cylindrical symmetry of the structure, the mesh is generated from hexahedral volume elements. The fine details of the electron spectrum and wavefunctions in the quantum dot are obtained as a function of macroscopic parameters such as the gate voltage, device geometry and doping level. The simulations provide comprehensive data for the analysis More >