Performance analysis of near-infrared-transparent perovskite solar cells employing heterojunction perovskite layers: Simulation study

In the evolving field of photovoltaic development, the dual goals of enhancing efficiency and reducing costs pose significant challenges. While perovskite photovoltaics hold promise, the adoption of innovative technologies is essential for further advancement. Multi-junction solar cells, which are pivotal in addressing these challenges, are hindered by a lack of efficient design strategies to optimize energy conversion. In this work, the field is developed by using SCAPS-1D program to conduct a detailed analysis of the intrinsic properties of Cs2AgBiBr6/ CsSnI3 heterojunction tandem device. The results indicate that after analyzing defect density, carrier lifetime, diffusion length, and recombination rate, the optimal defect density for the perovskite layer is 1 x 1014 cm-3. Further adjustments to the perovskite layer thickness reveal that the optimal thicknesses for Cs2AgBiBr6 and CsSnI3 are 50 nm and 350 nm, respectively. Comparative analysis of single-junction and multi-junction perovskite solar cells (PSCs) reveals that heterojunction tandem significantly enhances device performance. The proposed device structure (FTO/ZnOS/Cs2AgBiBr6/CsSnI3/P3HT/Au) achieves the optimal performance parameters, with a power conversion efficiency (PCE) of 33.70 %. Finally, the simulations assess the impact of variations in operational temperature and incident light intensity on cell performance, offering insights into the dynamics of multi-junction cells under actual working conditions. The findings show that the Cs2AgBiBr6/CsSnI3 heterojunction significantly broadens the device's photoresponse range. Additionally, the formation of interface energy level spikes at the Cs2AgBiBr6/ZnOS interface significantly reduces the recombination of photogenerated charge carriers, thereby improving the overall device efficiency. These insights tackle key issues on optimizing multi-junction PSCs and lay a foundation for future research aiming at achieving practical, high-performance, inorganic lead-free perovskite solar cells. Additionally, this work marks a significant step forward in developing sustainable and economically viable solar energy solutions.