Ikram Zidani

Modern multi-junction solar cell technology offers a pathway to achieving consistent and high photovoltaic conversion efficiencies through enhanced solar spectrum absorption. Indeed, during the last years, the industries of solar cells have focused on optimizing device structures, utilizing both robust and delicate materials to maximize their performances. This paper presents the modeling and optimization of the electrical and structural properties of high-efficiency InGaP/GaAs double-junction solar cells, specifically without employing an anti-reflective coating. This developed structure has been achieved by introducing a buffer layer in the lower layer and incorporating an upper back surface field layer into the investigated cell structure. Furthermore, the optimization conducted in this paper using Silvaco-Atlas software (version 2018) under the AM1.5G spectrum reveals that the proposed InGaP/GaAs tandem cell configuration exhibits significant performance, reaching conversion efficiency of 41.585%. It can be said that this adapted structure yields a short-circuit current density of 21.65 mA/cm², an open-circuit voltage of 2.319 V, and a filling factor of 84.001%. Whereas this newly optimized structure demonstrates its effectiveness in enhancing solar cell efficiency performance, presenting highly promising results with potential significance for the devices’ optical and electrical properties.

This study focuses on optimizing the performance of InGaP/GaAs dual-hetero junction solar cells (DHJSCs) through advanced material selection and structural modifications using the Silvaco–Atlas simulator. The baseline model, validated against theoretical and experimental benchmarks, served as a foundation for significant efficiency improvements. Key innovations include replacing conventional GaAs and InGaP emitters with AlGaAs and AlGaInP, respectively, which enhanced carrier collection and reduced recombination losses due to their superior material properties such as a larger bandwidth. Optimizations of thickness, doping concentration, and back surface field properties further minimized performance losses. These refinements resulted in an efficiency increase from 32.83% to 41.60%, with an additional rise to 42.68% at a reduced operating temperature of 15 °C. This work emphasizes the potential for achieving higher efficiencies and lower manufacturing costs by leveraging structural simulation to streamline solar cell design and development. The findings set a benchmark for future research and practical implementations in the field of high-efficiency photovoltaic technologies.

This study focuses on the simulation and optimization of an InGaP/GaAs dual-junction solar cells using Silvaco Atlas software, with a special emphasis on the incorporation of a hetero tunnel junction. The hetero-tunnel junction plays a pivotal role in enabling efficient charge carrier transport between the sub-cells, significantly improving the overall cell efficiency. Additionally, a new back-surface field (BSF) layer was integrated into the GaAs bottom sub-cell to further enhance performance. Various material combinations for the hetero-tunnel junction such as GaInP/GaAs, AlGaInP/GaInP, and AlGaInP/GaAs were systematically tested to assess their influence on device efficiency. The optimized structure demonstrated a short-circuit current density of 1.780 mA/cm², an open-circuit voltage of 2.310 V, a fill factor of 86.501%, and a conversion efficiency of 35.57% under AM1.5G illumination at 300 K. Recombination losses were minimized by the BSF layer optimization in the top and bottom cell, particularly with AlGaInP, leading to improved charge collection. Elevated temperatures were found to reduce both the open-circuit voltage and efficiency, highlighting the necessity of thermal management. These optimizations represent significant improvements over prior designs.

Cu(In,Ga)Se2 (CIGS)-based thin-film solar cells are currently among the most efficient. Zinc sulfide (ZnS) is the best buffer layer used in CIGS-based solar cells because it is non-toxic and has a wide band gap. In this study, we present a simulation of a CIGS solar cell with a ZnS buffer layer, carried out using the Silvaco-Atlas simulator. We attained an efficiency of 24.13%, short-circuit current of 37.81 mA/cm2, an open circuit voltage of 740 mV and a fill factor of 78.78% at a bandgap around 1.41 eV, corresponding to an x ratio of 0.5. The photovoltaic performance of the ZnS/CIGS solar cell is improved by optimizing the effects of layer parameters such as thickness, acceptor and donor densities of the CIGS absorber and ZnS buffer layers. For a 0.035 μm thick ZnS acceptor with a density of 6 × 1017 cm-3 and a 3 μm thick CIGS donor with a density of 1018 cm-3, a maximum efficiency improved to 27.22%.