Prediction of the photovoltaic performance of the lead-free layered Ruddlesden–Popper organic–inorganic perovskite (CH3NH3)2GeI4


  • K. Ouassoul Mohammed V Ubniversity in Rabat
  • A. El Kenz Mohammed V University in Rabat
  • M. Loulidi Mohammed V University in Rabat
  • A. Benyoussef Hassan II Academy of Sciences and Techniques
  • M. Azzouz Al Akhawayn University



Hybrid perovskite; ruddlesden-popper; DFT; quantum espresso; SLME; photovoltaic performance


Using the density functional theory (DFT) and the spectral limited maximum efficiency (SLME) model, we thoroughly evaluate the material MA2GeI4 as a prospective absorber for photovoltaic applications. This material belongs to the family of layered material organic-inorganic Ruddlesden-Popper perovskites, which have attracted interest due to their stability. Our first-principles calculations show that MA2GeI4 has a direct bandgap that is suitable for light absorption at 1.37 eV. To understand the source of its exceptional optical properties, the electronic structure, density of states, and optical properties were examined. Also, we used the SLME model to estimate the MA2GeI4 solar cell efficiency. The latter was found to be about 32.6% power conversion efficiency. The material’s excellent absorption and promising photovoltaic properties contribute to its high efficiency, even when quantum confinement occurs between layers. We found that MA2GeI4 is a potential absorber material for solar applications, demonstrating both good absorption characteristics and advantageous electrical properties. This discovery lays the path for additional experimental investigation of MA2GeI4 based solar cell.


S. Meloni et al., Ionic polarization-induced current–voltage hysteresis in ch3nh3pbx3 perovskite solar cells. Nature communications, 7 (2016) 10334,

M. A. Green, A. Ho-Baillie, and H. J. Snaith, The emergence of perovskite solar cells. Nature photonics, 8 (2014) 506,

C. Ma et al., 2d/3d perovskite hybrids as moisture-tolerant and efficient light absorbers for solar cells. Nanoscale, 8 (2016) 18309,

B. Feng, J. Duan, L. Tao, J. Zhang, and H. Wang, Enhanced performance in perovskite solar cells via bromide ion substitution and ethanol treatment. Applied Surface Science 430 (2018) 603,

E. Bi et al., Diffusion engineering of ions and charge carriers for stable efficient perovskite solar cells. Nature communications, 8 (2017) 15330,

Z. Meng, D. Guo, J. Yu, and K. Fan. Investigation of al2o3 and zro2 spacer layers for fully printable and hole-conductorfree mesoscopic perovskite solar cells. Applied Surface Science, 430 (2018) 632,

B. Abdollahi Nejand, V. Ahmadi, S. Gharibzadeh, and H. Reza Shahverdi, Cuprous oxide as a potential low-cost hole-transport material for stable perovskite solar cells. ChemSusChem, 9 (2016) 302,

C. Liu et al., High-efficiency and uv-stable planar perovskite solar cells using a low-temperature, solution-processed electron-transport layer. ChemSusChem, 11 (2018) 1232,

F. Matteocci et al., Encapsulation for long-term stability enhancement of perovskite solar cells. Nano Energy, 30 (2016) 162,

F. Arabpour Roghabadi et al., Stability progress of perovskite solar cells dependent on the crystalline structure: From 3d abx 3 to 2d ruddlesden–popper perovskite absorbers. J. Mat. Chem. A, 7 (2019) 5898,

C. Lan, Z. Zhou, R. Wei, and J. C. Ho, Two-dimensional perovskite materials: from synthesis to energy-related applications. Materials today energy 11 (2019) 61,

Y. Chen, Y. Sun, J. Peng, J. Tang, K. Zheng, and Z. Liang, 2d ruddlesden–popper perovskites for optoelectronics. Advanced Materials, 30 (2018) 1703487

D. H. Cao, C. C. Stoumpos, O. K. Farha, J. T. Hupp, and M. G. Kanatzidis, 2d homologous perovskites as light-absorbing materials for solar cell applications. Journal of the American Chemical Society, 137 (2015) 7843,

E. T. McClure, A. P. McCormick, and P. M. Woodward, Four lead-free layered double perovskites with the n= 1 ruddlesden–popper structure. Inorganic Chemistry,

(2020) 6010,

X. Hong, T. Ishihara, and A.V. Nurmikko, Dielectric confinement effect on excitons in pbi 4-based layered semiconductors. Physical Review B, 45 (1992) 6961,

X. Zhu et al., Vapor-fumigation for record efficiency twodimensional perovskite solar cells with superior stability. Energy Environ. Sci. 11 (2018) 3349,

Y. Li, First-Principles Study of Hybrid Halide Perovskites and Beyond for Optoelectronic Applications. (University of California, San Diego, 2020)

D. H Cao et al., Thin films and solar cells based on semiconducting two-dimensional ruddlesden–popper (ch3 (ch2) 3nh3) 2 (ch3nh3) n- 1sn n i3 n+ 1 perovskites. ACS Energy Letters, 2 (2017) 982,

K. P. Marshall, R. I. Walton, and R. A. Hatton, Tin perovskite/fullerene planar layer photovoltaics: improving the efficiency and stability of lead-free devices. Journal of materials chemistry A, 3 (2015) 11631,

L. Ma, M.-Gang Ju, J. Dai, and X. Cheng Zeng, Tin and germanium based two-dimensional ruddlesden–popper hybrid perovskites for potential lead-free photovoltaic and photoelectronic applications. Nanoscale, 10 (2018) 11314,

Z. Wang, A. M. Ganose, C. Niu, and D. O. Scanlon, First-principles insights into tin-based two-dimensional hybrid halide perovskites for photovoltaics. Journal of Materials Chemistry A, 6 (2018) 5652,

L. Wu, P. Lu, Y. Li, Y. Sun, J. Wong, and K. Yang, Firstprinciples characterization of two-dimensional (ch 3 (ch 2) 3 nh 3) 2 (ch 3 nh 3) n- 1 ge n i 3n+ 1 perovskite. Journal of Materials Chemistry A, 6 (2018) 24389,

I. U. l. Haq, G. Rehman, H. A. Yakout, and I. Khan, Structural and optoelectronic properties of ge- and si -based inorganic two dimensional ruddlesden popper halide perovskites. Materials Today Communications, 33 (2022) 104368,

D. B Mitzi, Synthesis, crystal structure, and optical and thermal properties of (c4h9nh3) 2mi4 (m= ge, sn, pb). Chemistry of materials, 8 (1996) 791,

P. Cheng et al., (c6h5c2h4nh3) 2gei4: a layered twodimensional perovskite with potential for photovoltaic applications. The journal of physical chemistry letters, 8 (2017) 4402,

B. R. Sutherland and E. H. Sargent, Perovskite photonic sources. Nature Photonics, 10 (2016) 295,

P. Giannozzi et al., Quantum espresso: a modular and opensource software project for quantum simulations of materials. Journal of physics: Condensed matter, 21 (2009) 395502,

P. E. Blöchl. Projector augmented-wave method. Physical review B, 50 (1994) 17953,

D.J. Chadi, Special points for brillouin-zone integrations. Physical Review B, 16 (1977) 1746,

M. Dion, H. Rydberg, E. Schröder, D. C. Langreth, and B. I. Lundqvist, Van der waals density functional for general geometries. Physical review letters, 92 (2004) 246401,

T. Thonhauser et al., Van der waals density functional: Selfconsistent potential and the nature of the van der waals bond. Physical Review B, 76 (2007) 125112,

G. Roman-Perez and J. M. Soler, Efficient implementation of a van der waals density functional: application to doublewall carbon nanotubes. Physical review letters, 103 (2009) 096102,

M. A. Perez-Osorio, A. Champagne, M. Zacharias, G.-M. Rignanese, and F. Giustino, Van der waals interactions and anharmonicity in the lattice vibrations, dielectric constants, effective charges, and infrared spectra of the organic–inorganic halide perovskite ch3nh3pbi3. The Journal of Physical Chemistry C, 121 (2017) 18459,

G. K. H. Madsen and D. J. Singh, Boltztrap a code for calculating band-structure dependent quantities. Computer Physics Communications, 175 (2006) 67,

L. Yu and A. Zunger, Identification of potential photovoltaic absorbers based on first-principles spectroscopic screening of materials. Physical review letters, 108 (2012) 068701,

W. Shockley and H. J. Queisser, Detailed balance limit of efficiency of p-n junction solar cells. Journal of applied physics, 32 (1961) 510,


American Society for Testing, Materials. Committee G03 on Weathering, and Durability. Standard tables for reference solar spectral irradiances: direct normal and hemispherical on 37A tilted surface. (ASTM international, 2003)

K. Emery and D. Myers, Reference solar spectral irradiance: air mass 1.5. ( Center, RERD, Ed, 2009)

H. Qu and X. Li, Temperature dependency of the fill factor in pv modules between 6 and 40 c. Journal of Mechanical Science and Technology, 33 (2019) 1981,

J. Qian et al., Spectroscopic limited practical efficiency (slpe) model for organometal halide perovskites solar cells evaluation. Organic Electronics, 59 (2018) 389,

S. Ruhle, Tabulated values of the shockley–queisser limit ¨ for single junction solar cells. Solar energy, 130 (2016) 139,

Khaoula Ouassoul, Abdallah El Kenz, Mohammed Loulidi, Abdelilah Benyoussef, and Mohamed Azzouz. Effect of orientation of the cation ch3nh3 on exciton’s mobility in ch3nh3pbi3. Chinese Journal of Physics, 80 (2022) 34,

D. Yang et al., Functionality-directed screening of pb-free hybrid organic-inorganic perovskites with desired intrinsic photovoltaic functionalities. Chemistry of Materials, 29 (2017) 524,

A. O. El-Ballouli, O. M. Bakr, and O. F. Mohammed, Structurally tunable two-dimensional layered perovskites: from confinement and enhanced charge transport to prolonged hot carrier cooling dynamics. The journal of physical chemistry letters, 11 (2020) 5705,

B. Cheng et al., Extremely reduced dielectric confinement in two-dimensional hybrid perovskites with large polar organics. Communications Physics, 1 (2018) 80, https://10.1038/s42005-018-0082-8

M. R. Filip, G. E. Eperon, H. J. Snaith, and F. Giustino, Steric engineering of metal-halide perovskites with tunable optical band gaps. Nature communications, 5 (2014) 5757,

K. Korshunova, L. Winterfeld, W. J. D. Beenken, and E. Runge, Thermodynamic stability of mixed pb: Sn methyl-ammonium halide perovskites. physica status solidi (b), 253 (2016) 1907,

P.S. Whitfield et al., Structures, phase transitions and tricritical behavior of the hybrid perovskite methyl ammonium lead iodide. Scientific reports, 6 (2016) 35685,

H. Mashiyama et al., Displacive character of the cubictetragonal transition in ch3nh3pbx3. Journal of the Korean Physical Society, 42 (2003) 1026

H. Kim et al., Direct observation of mode-specific phonon-band gap coupling in methylammonium lead halide perovskites. Nature communications, 8 (2017) 687,

M. Frenzel et al., Nonlinear thz control of the lead halide perovskite lattice. arXiv preprint arXiv:2301.03508, (2023),

R de L Kronig. On the theory of dispersion of x-rays. Josa, 12 (1926) 547,

H. Anthony Kramers, La diffusion de la lumiere par les atomes. In Atti Cong. Intern. Fisica (Transactions of Volta Centenary Congress) Como, 2 (1927) 545

R. Mayengbam, A. Srivastava, S.K. Tripathy, and G. Palai, Electronic structure and optical properties of gallium-doped hybrid organic–inorganic lead perovskites from first-principles calculations and spectroscopic limited maximum efficiencies. The J. Phys. Chem. C, 123 (2019) 23323,

P. Loper et al., Complex refractive index spectra of ch3nh3pbi3 perovskite thin films determined by spectroscopic ellipsometry and spectrophotometry. The journal of physical chemistry letters, 6 (2015) 66,

N. Baaalla, Y. Ammari, E.K. Hlil, R. Masrour, A. El Kenz, and A. Benyoussef, Study of optical, electrical and photovoltaic properties of ch3nh3pbi3 perovskite: ab initio calculations. Physica Scripta, 95 (2020) 095104,

N.M. Ravindra, P. Ganapathy, and J. Choi, Energy gap– refractive index relations in semiconductors–an overview. Infrared physics & technology, 50 (2007) 21,

M. Rai, L. Helena Wong, and L. Etgar, Effect of perovskite thickness on electroluminescence and solar cell conversion efficiency. The J. Phys. Chem. Lett., 11 (2020) 8189,

Z. Xiao, Q. Dong, C. Bi, Y. Shao, Y. Yuan, and J. Huang, Solvent annealing of perovskite-induced crystal growth for photovoltaic-device efficiency enhancement. Advanced Materials, 26 (2014) 6503,

W. E.I. Sha, X. Ren, L. Chen, and W. C.H. Choy, The efficiency limit of ch3nh3pbi3 perovskite solar cells. Applied Physics Letters, 106 (2015) 221104,

J. Klimes, and D. Bowler, and A. Michaelides, Van der Waals density functionals applied to solids. Bulletin of the American Physical Society, 56 (2011) 195131,

J. D. Head, and M. C. Zerner, A Broyden-Fletcher-GoldfarbShanno optimization procedure for molecular geometries. Chemical physics letters, 122 (1985) 1,

E. D. Murray, and K. Lee, and D. C. Langreth, Investigation of exchange energy density functional accuracy for interacting molecules J. Chem. Theory and Comp., 5 (2009) 2754,

Y. Shao et al., Unlocking surface octahedral tilt in twodimensional Ruddlesden-Popper perovskites Nature communications, 13 (2022) 138,



How to Cite

khaoula ouassoul, A. El Kenz, M. Loulidi, A. Benyoussef, and M. Azzouz, “Prediction of the photovoltaic performance of the lead-free layered Ruddlesden–Popper organic–inorganic perovskite (CH3NH3)2GeI4”, Rev. Mex. Fís., vol. 70, no. 4 Jul-Aug, pp. 040502 1–, Jul. 2024.