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.

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.

A new structure code for Spectral Amplitude Coding Optical Code Division Multiple Access (SAC–OCDMA) system with zero cross-correlation (ZCC) is presented in this paper. The principle idea of this method is based on the use of Zech logarithms in the construction of the code sequences to ensure orthogonality and compare their performances with previously reported codes. The maximum cross-correlation of this code is zero signifying that Multi-Access Interference (MAI) and Phase-Induced intensity noise (PIIN) effects are eliminated thus the system performances are improved. The BER simulation results against the total number of active users show a significant improvement in the performance of the proposed code over preceding reported codes. The system can accommodate more than 90 simultaneous users compared to other codes at a bit error rate of 10^(-9). Furthermore, the construction method offers good flexibility in the choice of the number of users, the weight, and the code length.