arXiv subjects

Md. Faiaad Rahman

Publications and source records attributed to Md. Faiaad Rahman.

3 recordsLinked to original sources

arXiv2026

Advancing Lead-Free FASnI3 Perovskite Solar Cells via Cu-Doped NiOx HTL Engineering: An Optoelectronic Analysis

Efficient lead-free perovskite solar cells remain limited by inefficient charge transport and significant recombination losses. In this work, copper (Cu) doped nickel oxide (NiOx) is employed as the hole transport layer (HTL) in a formamidinium tin iodide (FASnI3) perovskite solar cell to improve hole extraction and suppress carrier losses. The optoelectronic response of the proposed device architecture is evaluated through a coupled numerical framework combining finite-difference time-domain (FDTD) optical simulations with finite element method (FEM)-based electrical modeling. Electrical analysis solves the Poisson equation together with the drift-diffusion and carrier continuity equations, while accounting for radiative, non-adiative, and interfacial recombination mechanisms. Systematic optimization of the thicknesses and doping concentrations of the constituent layers was performed to establish a high-performance device configuration. Following optimization of layer dimensions and carrier densities, the device achieved a power conversion efficiency (PCE) of 24.71%. Integrating an anti-reflection coating (ARC) effectively suppressed reflection losses, yielding a 5.47% relative enhancement in PCE. Consequently, the optimized device achieved a peak PCE of 26.06%, with a short-circuit current density (Jsc) of 28.98 mA/cm2, an open-circuit voltage (Voc) of 1.051 V, and a fill factor (FF) of 85.64%. These findings demonstrate that Cu-doped NiOx functions as a highly promising HTL to boost charge collection and maximize overall efficiency in lead-free FASnI3 solar cells.

physics.app-ph↗

arXiv2025

Unveiling architectural and optoelectronic synergies in lead-free perovskite/perovskite/kesterite triple-junction monolithic tandem solar cells

The widespread use of lead-based materials in tandem solar cells raises critical environmental and health concerns due to their inherent toxicity and risk of contamination. To address this challenge, we focused on lead-free tandem architectures based on non-toxic, environmentally benign materials such as tin-based perovskites and kesterites, which are essential for advancing sustainable photovoltaic technologies. In this study, we present the proposition, design, and optimization of two distinct lead-free monolithic tandem solar cell architectures - an all-perovskite dual-junction device employing potassium tin iodide (KSnI3) and formamidinium tin triiodide (FASnI3) as absorbers for the top and bottom subcells, respectively, and a triple-junction monolithic tandem structure incorporating KSnI3, FASnI3, and Ag-doped copper zinc tin selenide (ACZTSe) as absorbers for the top, middle, and bottom subcells, respectively. We simulated the optical and electrical characteristics of these devices using the finite-difference time-domain and finite element methods, explicitly considering radiative, non-radiative, and surface recombination mechanisms. The optimized all-perovskite dual-junction solar cell achieved a power conversion efficiency (PCE) of 27.3%, with short-circuit current density (Jsc) of 14.74 mA/cm2, open-circuit voltage (Voc) of 2.227 V, and fill factor (FF) of 83.14%. Conversely, the optimized triple-junction hybrid perovskite-kesterite architecture secured an elevated PCE of 30.69%, along with Jsc of 13.184 mA/cm2, Voc of 2.766 V, and FF of 84.18%. These findings reveal the strong potential of lead-free perovskite and kesterite material based absorbers in promoting high-performance hybrid tandem solar cells, highlighting their importance in advancing sustainable and efficient photovoltaic technologies.

physics.optics↗

arXiv2025

Hierarchically structured, high-efficiency and thermally robust perovskite solar cells with band-engineered double-hole layers

Despite the promising optoelectronic properties of methylammonium lead iodide (MAPbI3)-based perovskite solar cells (PSCs), their commercial viability is hindered by interfacial energy misalignment, suboptimal light absorption, and thermal instability. Here, we present a comprehensive theoretical framework to enhance the power conversion efficiency (PCE) of MAPbI3 based PSC through integrated electronic and morphological engineering. Firstly, to address interfacial recombination and inefficient hole extraction at the perovskite/HTL junction, we introduced a double hole transport layer (HTL) stack comprising CuO and I2O5-doped Spiro-OMeTAD, which significantly improved energy level alignment and carrier selectivity. Comprehensive multiphysics simulations, combining finite-difference time-domain (FDTD) optical analysis with finite element method (FEM) based electrical and thermal modeling, demonstrated that optimized doping concentrations and thickness parameters within the CuO/Spiro-OMeTAD hole transport layers can enhance the PCE to 22.78%. However, planar architectures, while offering ease of fabrication and scalability, exhibit weak near-UV and near-infrared absorption, whereas nanostructures attain superior light trapping but incur significant fabrication complexity, underscoring the need for balanced design strategies. To address these inherent limitations, we propose a hierarchical ellipsoidal patterned solar cell (HEPSC), wherein a top-layer ellipsoidal nanostructure is introduced across the full device stack. This design enhances broadband light trapping and optical confinement throughout the active layers while maintaining fabrication feasibility through geometrically realistic structuring.

physics.optics↗