Nontoxic Quantum Dot Solar Cells: Pioneering High‐Efficiency Tandem Solutions for Sustainable Energy

The quest for ecofriendly solar technology has propelled the development of nontoxic quantum dot solar cells (QDSCs). In this article, we present a comprehensive analysis and optimization of 18 QDSC configurations, utilizing environmentally benign materials. Copper zinc tin sulfide (CZTS) and copper indium disulfide (CuInS 2 ) quantum dots serve as absorber layers, paired with nontoxic electron and hole transport layers. Our optimized configuration, featuring FTO/SnO 2 /CuInS 2 ‐QD/Cu 2 O/Au, achieves a power conversion efficiency (PCE) of 25.77% under standard conditions. Advanced simulations reveal that efficiency losses due to parasitic resistances are mitigated by incorporating optical filters, enhancing by 1.38% of the PCE. Furthermore, tandem integration of CuInS 2 ‐QD and CZTS‐QD devices in series results in an efficiency of 47.36%, demonstrating the potential for an efficient energy harvesting. Addressing temperature sensitivity and resistive losses, we propose innovative hybrid systems and material modifications to enhance operational stability. This article contributes to the development of sustainable and efficient QDSCs, aligning with global renewable energy goals while prioritizing environmental safety.