GrapheneEnhanced (BA)₂SnI₄ Dataset

Using Quantum ESPRESSO, we first examine the electronic and thermoelectric properties of pristine (BA)₂SnI₄, followed by a systematic analysis of graphene/(BA)₂SnI₄ heterostructures to assess changes in electronic structure, charge transfer, and transport behavior.(Results and Discussion) The results show that graphene integration significantly modifies the electronic structure, enhancing charge carrier mobility and electrical conductivity.

Pristine (BA)₂SnI₄ exhibits a high Seebeck coefficient and a maximum power factor of 1.6 × 10⁻² W·m⁻¹·K⁻² at 100 K, indicating strong potential for low-temperature thermoelectric applications. However, performance declines at higher temperatures, with the power factor stabilizing at lower values above 600 K. Graphene incorporation introduces metallic characteristics and enhances states near the Fermi level, improving charge transfer and reducing recombination losses.

The single-layer graphene system shows relatively stable power factor values across a wide temperature range, while the double-layer configuration exhibits slightly lower but similarly stable performance.(Conclusion) Overall, these findings demonstrate that graphene–perovskite heterostructures offer a promising pathway for developing stable, lead-free, and high-performance thermoelectric materials, particularly for low-temperature applications, and provide valuable insights for the design of next-generation 2D perovskite-based devices.