Journal of Ultrafine Grained and Nanostructured Materials

Journal of Ultrafine Grained and Nanostructured Materials

Bandgap-Engineered MAPb1-ySnyI3 Absorbers via Pb/Sn Compositional Grading for High-Efficiency Perovskite Solar Cells

Document Type : Research Paper

Authors
Ali Baghban Parashkouh
Ali Sadr
School of Electrical Engineering, Iran University of Science and Technology, Tehran, 13114-16846, Iran
10.22059/jufgnsm.2026.01.07
Abstract
Compositional grading of the MAPb1-ySnyI3 absorber layers via controlled variation of the Pb/Sn ratio provides a pathway to enhance band alignment, and mitigate recombination in perovskite solar cells (PSCs). In this study, an optimized grading model for the MAPb1-ySnyI3 PSC is designed and simulated using SCAPS. Compounds with higher bandgap energies (Eg) are employed near the absorber/electron transporting layer (ABS/ETL), and hole transporting layer/absorber (HTL/ABS) interfaces to control the recombination rate. To enhance carrier generation, lower Eg materials are incorporated at the central regions of the absorber layer. By exploring y = 0, 0.5, and 1 as the grading end materials, the best model with power conversion efficiency (PCE) of 28.86% is achieved using 0.5<y<1, and optimized grading depth of the absorber layer. This model improves the PCE of MAPbI3 and MASnI3 devices by around 22.7%, and 31.4%, respectively. Finally, a parabolic grading is employed to simulate the experimental transition of Eg between 1.18 eV and 1.3 eV.
Keywords
Perovskite solar cell
Absorber material
Bandgap grading
Compositional grading
  1. Salah, M.M., et al., A comparative study of different ETMs in perovskite solar cell with inorganic copper iodide as HTM. Optik, 2019. 178: p. 958-963.
  2. Mandadapu, U., et al., Design and simulation of high efficiency tin halide perovskite solar cell. International Journal of Renewable Energy Research, 2017. 7(4): p. 1603-1612.
  3. Casas, G., et al., Analysis of the power conversion efficiency of perovskite solar cells with different materials as Hole-Transport Layer by numerical simulations. Superlattices and Microstructures, 2017. 107: p. 136-143.
  4. Bansal, S. and P. Aryal. Evaluation of new materials for electron and hole transport layers in perovskite-based solar cells through SCAPS-1D simulations. in 2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC). 2016. IEEE.
  5. Mandadapu, U., S.V. Vedanayakam, and K. Thyagarajan, Simulation and analysis of lead based perovskite solar cell using SCAPS-1D. Indian Journal of Science and Technology, 2017. 10(11): p. 65-72.
  6. Parashkouh, A.B., et al., Improved Lead Halide Perovskite Films and Devices Using Hot-Flow-Assisted Annealing. IEEE Journal of Photovoltaics, 2025.
  7. Park, J., et al., Controlled growth of perovskite layers with volatile alkylammonium chlorides. Nature, 2023. 616(7958): p. 724-730.
  8. Green, M.A., et al., Solar cell efficiency tables (version 66). Progress in Photovoltaics, 2025. 33(NREL/JA--5900-94273).
  9. Gholipour, S. and M. Saliba, Bandgap tuning and compositional exchange for lead halide perovskite materials, in Characterization Techniques for Perovskite Solar Cell Materials. 2020, Elsevier. p. 1-22.
  10. Prasanna, R., et al., Band gap tuning via lattice contraction and octahedral tilting in perovskite materials for photovoltaics. Journal of the American Chemical Society, 2017. 139(32): p. 11117-11124.
  11. Ferrara, C., et al., Wide band-gap tuning in Sn-based hybrid perovskites through cation replacement: the FA 1− x MA x SnBr 3 mixed system. Journal of Materials Chemistry A, 2017. 5(19): p. 9391-9395.
  12. Konstantakou, M. and T. Stergiopoulos, A critical review on tin halide perovskite solar cells. Journal of Materials Chemistry A, 2017. 5(23): p. 11518-11549.
  13. Owolabi, J.A., et al., Investigating the Effect of ZnSe (ETM) and Cu2O (HTM) on Absorber Layer on the Performance of Pervoskite Solar Cell Using SCAPS-1D. Am J Phys Appl, 2020. 8(1): p. 1.
  14. Mehra, S., et al., Evaluating Pb-based and Pb-free halide perovskites for solar-cell applications: a simulation study. Heliyon, 2024. 10(12).
  15. Kapil, G., et al., Highly efficient 17.6% tin–lead mixed perovskite solar cells realized through spike structure. Nano letters, 2018. 18(6): p. 3600-3607.
  16. Xu, G., et al., Integrating ultrathin bulk‐heterojunction organic semiconductor intermediary for high‐performance low‐bandgap perovskite solar cells with low energy loss. Advanced Functional Materials, 2018. 28(42): p. 1804427.
  17. Cao, J., et al., High‐performance tin–lead mixed‐perovskite solar cells with vertical compositional gradient. Advanced Materials, 2022. 34(6): p. 2107729.
  18. Liu, H., et al., Indium Iodide Additive Realizing Efficient Mixed Sn─ Pb Perovskite Solar Cells. Advanced Energy Materials, 2024. 14(17): p. 2304234.
  19. Wang, A., X. Gan, and J. Yu, Simulation of narrow-bandgap mixed Pb–Sn perovskite solar cells with inverted pin structure. Optical Materials, 2021. 112: p. 110751.
  20. Zhang, W., et al., Revealing key factors of efficient narrow-bandgap mixed lead-tin perovskite solar cells via numerical simulations and experiments. Nano Energy, 2022. 96: p. 107078.
  21. Al Husseini, H.B. and A.M. Jafar, An analysis comparing the performance of lead and tin halides organic perovskite solar cells and numerical simulation with SCAPS. Optical Materials, 2024. 155: p. 115814.
  22. Rahaman, M., et al., Numerical optimization of lead-based and lead-free absorber materials for perovskite solar cell (PSC) architectures: A SCAPS-1D simulation. AIP Advances, 2024. 14(9).
  23. Moone, P.K. and N. Sharifi, Comparison of Pb-based and Sn-based perovskite solar cells using SCAPS simulation: optimal efficiency of eco-friendly CsSnI3 devices. Environmental Science and Pollution Research, 2024. 31(39): p. 51447-51460.
  24. Sadullah, M. and K. Ghosh, Bandgap tuning and performance analysis of hybrid MAPb1− xSnxI3 perovskite solar cell: A numerical approach. Optik, 2024. 300: p. 171644.
  25. Luo, W., et al., Optimization of vertical gradient Pb-Sn hybrid perovskite solar cells using SCAPS (Solar Cell Capacitance Simulator). Materials Today Communications, 2024. 39: p. 108894.
  26. Bai, L., et al., Optimization of Sn defects through multiple coordination effect to realize stable Sn–Pb mixed perovskite solar cells. Solar Energy Materials and Solar Cells, 2023. 254: p. 112283.
  27. Badrooj, M., F. Jamali-Sheini, and N. Torabi, Roles of Sn content in physical features and charge transportation mechanism of Pb-Sn binary perovskite solar cells. Solar Energy, 2020. 209: p. 590-601.
  28. Badrooj, M., F. Jamali-Sheini, and N. Torabi, Zn-doped Pb/Sn hybrid perovskite solar cells: Towards high photovoltaic performance. Solar Energy, 2022. 236: p. 63-74.
  29. Guli, M., et al., Effect of ABX 3 site changes on the performance of tin–lead mixed perovskite solar cells. Nanoscale, 2024. 16(37): p. 17276-17299.
  30. Yin, C., et al., Numerical investigation of eco-friendly FASnI3 perovskite solar cells: Effects of energy band alignment and interface defect. Micro and Nanostructures, 2025. 203: p. 208147.
  31. Hao, F., et al., Anomalous band gap behavior in mixed Sn and Pb perovskites enables broadening of absorption spectrum in solar cells. Journal of the American Chemical Society, 2014. 136(22): p. 8094-8099.
  32. Anaya, M., et al., Optical analysis of CH 3 NH 3 Sn x Pb 1− x I 3 absorbers: a roadmap for perovskite-on-perovskite tandem solar cells. Journal of Materials Chemistry A, 2016. 4(29): p. 11214-11221.
  33. Zhao, B., et al., High open‐circuit voltages in tin‐rich low‐bandgap perovskite‐based planar heterojunction photovoltaics. Advanced materials, 2017. 29(2): p. 1604744.
  34. Yang, Z., A. Rajagopal, and A.K.Y. Jen, Ideal bandgap organic–inorganic hybrid perovskite solar cells. Advanced Materials, 2017. 29(47): p. 1704418.
  35. Zhu, H.L., et al., Controllable Crystallization of CH3NH3Sn0. 25Pb0. 75I3 Perovskites for Hysteresis‐Free Solar Cells with Efficiency Reaching 15.2%. Advanced Functional Materials, 2017. 27(11): p. 1605469.
  36. Li, L., et al., High efficiency planar Sn–Pb binary perovskite solar cells: controlled growth of large grains via a one-step solution fabrication process. Journal of Materials Chemistry C, 2017. 5(9): p. 2360-2367.
  37. Li, Y., et al., 50% Sn‐Based Planar Perovskite Solar Cell with Power Conversion Efficiency up to 13.6%. Advanced Energy Materials, 2016. 6(24): p. 1601353.
  38. Ogomi, Y., et al., CH3NH3Sn x Pb (1–x) I3 Perovskite solar cells covering up to 1060 nm. The journal of physical chemistry letters, 2014. 5(6): p. 1004-1011.
  39. Hossain, M.F., M. Faisal, and H. Okada. Device modeling and performance analysis of perovskite solar cells based on similarity with inorganic thin film solar cells structure. in 2016 2nd International Conference on Electrical, Computer & Telecommunication Engineering (ICECTE). 2016. IEEE.
  40. Anwar, F., et al., Effect of different HTM layers and electrical parameters on ZnO nanorod-based lead-free perovskite solar cell for high-efficiency performance. International Journal of Photoenergy, 2017. 2017.
  41. Minemoto, T. and M. Murata, Theoretical analysis on effect of band offsets in perovskite solar cells. Solar Energy Materials and Solar Cells, 2015. 133: p. 8-14.
  42. Samiee, M., et al., Defect density and dielectric constant in perovskite solar cells. Applied Physics Letters, 2014. 105(15).
  43. Lenka, T., et al., Numerical analysis of high-efficiency lead-free perovskite solar cell with NiO as hole transport material and PCBM as electron transport material. CSI Transactions on ICT, 2020. 8: p. 111-116.
  44. Somay, S., A. Kumar, and S.K. Pandey, Design perspective and numerical analysis of all perovskite 2-terminal and 4-terminal tandem solar cell. Micro and Nanostructures, 2022. 167: p. 207240.
  45. Karthick, S., S. Velumani, and J. Bouclé, Experimental and SCAPS simulated formamidinium perovskite solar cells: A comparison of device performance. Solar Energy, 2020. 205: p. 349-357.
  46. Burgelman, M., et al., SCAPS manual. 2016, February.
  47. Wu, D.T., et al., Enhancing the Efficiency and Stability of Tin‐Lead Perovskite Solar Cells via Sodium Hydroxide Dedoping of PEDOT: PSS. Small Methods, 2024. 8(12): p. 2400302.
  48. Yang, D., et al., Stable efficiency exceeding 20.6% for inverted perovskite solar cells through polymer-optimized PCBM electron-transport layers. Nano letters, 2019. 19(5): p. 3313-3320.
  49. Zhong, Y., et al., Role of PCBM in the Suppression of Hysteresis in Perovskite Solar Cells. Advanced Functional Materials, 2020: p. 1908920.
  50. Fahsyar, P.N.A., et al., Correlation of simulation and experiment for perovskite solar cells with MoS2 hybrid-HTL structure. Applied Physics A, 2021. 127(5): p. 1-10.
  51. Azri, F., et al., Electron and hole transport layers optimization by numerical simulation of a perovskite solar cell. Solar energy, 2019. 181: p. 372-378.
  52. Haider, S.Z., H. Anwar, and M. Wang, A comprehensive device modelling of perovskite solar cell with inorganic copper iodide as hole transport material. Semiconductor Science and Technology, 2018. 33(3): p. 035001.
  53. Lin, L., et al., Modeling and analysis of HTM-free perovskite solar cells based on ZnO electron transport layer. Superlattices and Microstructures, 2017. 104: p. 167-177.
  54. Husainat, A., et al., Simulation and analysis of methylammonium lead iodide (CH3NH3PbI3) perovskite solar cell with Au contact using SCAPS 1D simulator. American Journal of Optics and Photonics, 2019. 7(2): p. 33.
  55. Dullweber, T., U. Rau, and H. Schock, A new approach to high-efficiency solar cells by band gap grading in Cu (In, Ga) Se2 chalcopyrite semiconductors. Solar Energy Materials and Solar Cells, 2001. 67(1-4): p. 145-150.
  56. Fu, S., et al., Synergistic bimolecular erosion-healing interfacial passivation for wide-bandgap perovskite and tandem solar cells. Science Bulletin, 2025. 70(11): p. 1786-1792.
  57. Chen, C., et al., High performance wide-bandgap perovskite solar cells based on bulk and top surface dual passivation. Chemical Engineering Journal, 2025: p. 169605.
  58. Huang, Z., et al., Band engineering via gradient molecular dopants for CsFA perovskite solar cells. Advanced Functional Materials, 2021. 31(18): p. 2010572.
  59. Hu, M., et al., Post‐treatment of metal halide perovskites: from morphology control, defect passivation to band alignment and construction of heterostructures. Advanced Energy Materials, 2023. 13(41): p. 2301888.
  60. Khorshidi, E., et al., Antisolvent additive engineering for boosting performance and stability of graded heterojunction perovskite solar cells using amide-functionalized graphene quantum dots. ACS applied materials & interfaces, 2022. 14(49): p. 54623-54634.
  61. Wang, H., et al., Additive Engineering for mixed lead–tin narrow-band-gap perovskite solar cells: Recent advances and perspectives. Energy & Fuels, 2023. 37(9): p. 6401-6423.
  62. Dixit, H., D. Punetha, and S.K. Pandey, Improvement in performance of lead free inverted perovskite solar cell by optimization of solar parameters. Optik, 2019. 179: p. 969-976.
  63. Mandadapu, U., et al., Optimisation of high efficiency tin halide perovskite solar cells using SCAPS-1D. International journal of simulation and process modelling, 2018. 13(3): p. 221-227.
  64. Mari, B. and K.R. Adhikari, Numerical Simulations on Perovskite Photovoltaic Devices. Chapters, 2016.
  65. Singh, M., R. Kumar, and V. Singh, Graphene as charge transport layers in lead free perovskite solar cell. Materials Research Express, 2019. 6(11): p. 115611.
  66. Cho, K.T., et al., Highly efficient perovskite solar cells with a compositionally engineered perovskite/hole transporting material interface. Energy & Environmental Science, 2017. 10(2): p. 621-627.
  67. Bai, Y., et al., Dimensional engineering of a graded 3D–2D halide perovskite interface enables ultrahigh Voc enhanced stability in the p‐i‐n photovoltaics. Advanced Energy Materials, 2017. 7(20): p. 1701038.
Journal of Ultrafine Grained and Nanostructured Materials
Volume 59, Issue 1
June 2026
Pages 90-103

  • Receive Date 25 February 2026
  • Revise Date 20 April 2026
  • Accept Date 25 April 2026