arXiv subjects

Md. Abdur Rashid

Publications and source records attributed to Md. Abdur Rashid.

3 recordsLinked to original sources

arXiv2026

Design and numerical performance analysis of efficient Ag3TaX4 (X = S, Se, Te) thin film solar cells

Silver-based ternary chalcogenides have recently emerged as promising absorber materials for thin film photovoltaics. Nevertheless, their photovoltaic performance in complete device architectures has not yet been systematically explored. In this work, three-dimensional (3D) n-CdS/p-Ag3TaX4 (X = S, Se, Te)/p+-GeS thin-film solar cells have been designed and numerically investigated using the Semiconductor Module of COMSOL Multiphysics. Herein, the various performance matrices of the proposed devices have been analysed in accordance with the changing of depth, carrier, and defect concentration in each layer of the structures. The optimized Ag3TaS4-based device delivers a power conversion efficiency, PCE of 24.66%, open circuit voltage, VOC of 1.4V, short circuit current density, JSC of 20.68 mA/cm2, and fill factor, FF of 85.16%. The Ag3TaSe4-based solar cell exhibits the PCE of 28.1% with VOC = 1.19V, JSC = 27.0 mA/cm2, and FF = 87.44%. The Ag3TaTe4 solar device shows a PCE of 27.56% with a VOC of 0.88 V, JSC of 36.14 mA/cm2, fill factor of 86.65%. These results provide a deeper insight into device operation and offer practical design guidelines for fabricating efficient Ag3TaX4 (X = S, Se, T e)-based novel next-generation solar cells.

physics.optics↗

arXiv2026

First-principles insights into the optoelectronic and thermoelectric properties of X3NbY4(X= Cu, Ag, Au; Y=S, Se, Te) sulvanite compounds for energy applications

The structural, electronic, optical and transport properties of X3NbY4(X= Cu, Ag, Au; Y=S, Se, Te) sulvanite chalcogenides materials have been investigated using the Full Potential Linear Augmented Plane wave (FP-LAPW) within the density functional theory (DFT). The calculated structural information of X3NbY4 compounds is consistent with reported results of the same family compounds. The electronic band diagram exhibit indirect type band structures with bandgap value in the range of Eg 1.65- 0.50 eV using PBE-GGA functional and 1.80 eV-1.18 eV using TB-mBJ functional which indicates that these are semiconductor materials. The density of states (DOS) shows that the amount of bandgap decreases owing to move of valence band maximum (VBM) to the high energy level whereas the conduction band minimum (CBM) to the low energy level owing to the replacement of S-S-Te and Cu-Ag-Au atoms. The hybridized orbital by X-d, Nb-d and Y-p atomic orbitals dominate the VBM while hybridized by Nb-d and Y-p atomic orbitals mainly contribute the CBM. The elastic calculations exhibit that Cu-based materials have brittleness nature whereas Ag- and Au-based compounds are ductile nature. Furthermore, the phonon dispersion curves probes that these X3NbY4 compounds are dynamically stable. However, the calculated optical properties: dielectric function, absorption coefficient, refractive index, and energy loss function; specifically, the higher value of absorption coefficient (105 cm-1) indicates that these materials are attractive candidates in optoelectronics applications. Finally, thermoelectric parameters such as Seebeck coefficient, thermal conductivity, electrical conductivity, power factor (P.F) and ZT value of these compounds have also been investigated. Overall, the finding explores that these materials are potential candidates for the applications in optoelectronic and thermoelectric devices.

cond-mat.mtrl-sci↗

arXiv2023

Quantized Hall conductance in graphene by nonperturbative magnetic-field-containing relativistic tight-binding approximation method

In this study, we conducted a numerical investigation on the Hall conductance ($σ_{Hall}$) of graphene based on the magnetic energy band structure calculated using a nonperturbative magnetic-field-containing relativistic tight-binding approximation (MFRTB) method. The nonperturbative MFRTB can revisit two types of plateaus for the dependence of $σ_{Hall}$ on Fermi energy. One set is characterized as wide plateaus (WPs). These WPs have filling factors (FFs) of 2, 6, 10, 14, etc. and are known as the half-integer quantum Hall effect. The width of WPs decreases with increasing FF, which exceeds the decrease expected from the linear dispersion relation of graphene. The other set is characterized by narrow plateaus (NPs), which have FFs of 0, 4, 8, 12, etc. The NPs correspond to the energy gaps caused by the spin-Zeeman effect and spin-orbit interaction. Furthermore, it was discovered that the degeneracy of the magnetic energy bands calculated using the nonperturbative MFRTB method leads to a quantized $σ_{Hall}$.

cond-mat.mes-hall↗