Abstract
This paper deals with the numerical performance evaluation of solar cells based on ZnMgO/CZTS with and without a back-surface field (BSF) layer. ZnMgO is used as a buffer layer due to its non-toxicity and strain-balancing properties at i-ZnO/ZnMgO and ZnMgO/CZTS interfaces. A multilayer structure of ZnO: Al/i-ZnO/ZnMgO/CZTS is considered for the initial analysis. Subsequently, a BSF layer of CZTS material with different optical and electronic properties, called CZTS2, is inserted between the back-contact layer and the existing CZTS layer, called CZTS1, to form a new structure as ZnO: Al/i-ZnO/ZnMgO/CZTS1/CZTS2 to enhance the performance. The performance of the structure with and without the BSF layer was evaluated in terms of various layer parameters such as thickness, band gap, carrier concentration, defect densities, and work function. Then, the effects of operating temperature and the combination of shunt and series resistance on the overall performance were investigated. The simulated results were calibrated with existing experimental data from the literature to validate the work. In the optimized structure with the BSF layer, a maximum efficiency of 23.67% is achieved, which is 4% higher than that of without the BSF layer. The generation and recombination rates of the structures with and without the BSF layer were investigated to understand the reason for the improved efficiency. The results of this work are very promising for the development of high-efficiency, low-cost, and non-toxic CZTS solar cells.
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References
Dakua, P. K. & Panda, D. K. Analysis of various hole transport layers (HTLs) on the performance of CZTS- solar cell. Phys. Scr. 98 (3), 035110. https://doi.org/10.1088/1402-4896/acbbad (Feb. 2023).
K. Pal, P. Singh, A. Bhaduri, and K. B. Thapa, Current challenges and future prospects for a highly efficient (>20%) kesterite CZTS solar cell: A review, Solar Energy Materials and Solar Cells, vol. 196, pp. 138–156, Apr. 2019, doi: 10.1016/j.solmat.2019.03.001.
Grossberg, M. et al. The electrical and optical properties of kesterites. J. Phys. Energy. 1 (4), 044002. https://doi.org/10.1088/2515-7655/ab29a0 (Jun. 2019).
Nazligul, S., Wang, M. & Choy, K. L. Recent development in Earth-Abundant kesterite materials and their applications. Sustainability 12 (12), 5138. https://doi.org/10.3390/su12125138 (Jun. 2020).
Jhuma, F. A., Shaily, M. Z. & Rashid, M. J. Towards high-efficiency CZTS solar cell through buffer layer optimization. Mater. Renew. Sustainable Energy. 8 (1). https://doi.org/10.1007/s40243-019-0144-1 (Feb. 2019).
Rahman, S., Islam, A., Khandaker, T., Hossain & Rashid, M. J. Bilayer CZTS/Si absorber for obtaining highly efficient CZTS solar cell. Sol. Energy. 230, 1189–1198. https://doi.org/10.1016/j.solener.2021.11.021 (Nov. 2021).
AlZoubi, T. & Moustafa, M. Numerical optimization of absorber and cds buffer layers in CIGS solar cells using SCAPS. Int. J. Smart Grid Clean. Energy. 291–298. https://doi.org/10.12720/sgce.8.3.291-298 (Jan. 2019).
Wang, W. et al. Device characteristics of CZTSSe Thin-Film solar cells with 12.6% efficiency. Adv. Energy Mater. 4 (7). https://doi.org/10.1002/aenm.201301465 (Nov. 2013).
Shockley, W., Queisser, H. J. & Photovoltaics, L. Detailed Balance Limit of Efficiency of p-n Junction Solar Cells, [Online]. (1961). Available: https://static.sif.it/SIF/resources/public/files/energy2021/Siebentritt2.pdf
Hossain, M. I. et al. Perovskite/Silicon tandem solar cells: from detailed balance limit calculations to photon management. Nano-Micro Lett. 11 (1), 58. https://doi.org/10.1007/s40820-019-0287-8 (Jul. 2019).
Zhao, W., Zhou, W. & Miao, X. Numerical simulation of CZTS thin film solar cell. pp. 502–505. (2012). https://doi.org/10.1109/nems.2012.6196826
Tripathi, S., Sadanand, N., Lohia, P. & Dwivedi, D. K. Contribution to sustainable and environmental friendly non-toxic CZTS solar cell with an innovative hybrid buffer layer. Sol. Energy. 204, 748–760. https://doi.org/10.1016/j.solener.2020.05.033 (May 2020).
Khalate, S. A., Kate, R. S. & Deokate, R. J. A review on energy economics and the recent research and development in energy and the Cu2ZnSnS4 (CZTS) solar cells: A focus towards efficiency. Sol. Energy. 169, 616–633. https://doi.org/10.1016/j.solener.2018.05.036 (May 2018).
Liu, F. et al. Beyond 8% ultrathin kesterite Cu2ZnSnS4 solar cells by interface reaction route controlling and self-organized nanopattern at the back contact. NPG Asia Mater. 9 (7), e401. https://doi.org/10.1038/am.2017.103 (Jul. 2017).
Mohammadnejad, S., Bahnamiri, Z. M. & Maklavani, S. E. Enhancement of the performance of kesterite thin-film solar cells using dual absorber and ZnMgO buffer layers. Superlattices Microstruct. 144, 106587. https://doi.org/10.1016/j.spmi.2020.106587 (2020).
Tajima, S., Itoh, T., Hazama, H., Ohishi, K. & Asahi, R. Improvement of the open-circuit voltage of Cu2ZnSnS4solar cells using a two-layer structure, Applied Physics Express 8 (8), 082302.https://doi.org/10.7567/apex.8.082302 (2015).
Saha, U. & Alam, M. K. Boosting the efficiency of single junction kesterite solar cell using ag mixed Cu2ZnSnS4 active layer. RSC Adv. 8 (9), 4905–4913. https://doi.org/10.1039/c7ra12352c (Jan. 2018).
Benzetta, E. H., Abderrezek, M. & Djeghlal, M. E. A comparative study on generation and recombination process of kesterite CZTS based thin film solar cells for different designs. Optik 219, 165300. https://doi.org/10.1016/j.ijleo.2020.165300 (Jul. 2020).
Mazumder, S., Mazumder, P. & Senthilkumar, K. Device modeling and study of AZO/i-ZnO/ZnS/CZTS-bilayer solar cell for different series and shunt resistances. Sol. Energy. 245, 46–57. https://doi.org/10.1016/j.solener.2022.08.055 (Sep. 2022).
Dakua, P. K. & Panda, D. K. Implementation of Zinc Sulfide (ZnS) as a Suitable Buffer Layer for CZTS Solar Cell from Numerical Analysis, in Lecture notes in electrical engineering, pp. 257–264. (2022). https://doi.org/10.1007/978-981-19-2308-1_27
Hu, Y. et al. The impact of Mg content on the structural, electrical and optical properties of MgZnO alloys: A first principles study. Curr. Appl. Phys. 15 (3), 423–428. https://doi.org/10.1016/j.cap.2015.01.015 (Jan. 2015).
Park, S. H., Ahn, D., Kang, T. W. & Lee, S. J. Optoelectronic Applications of ZnO/ZnMgO Quantum well Lasers in the Blue and the UV Spectral Regions, AIP Conference Proceedings, vol. 893, pp. 261–262, Jan. (2007). https://doi.org/10.1063/1.2729867
Todorov, T. K. et al. Ultrathin high band gap solar cells with improved efficiencies from the world’s oldest photovoltaic material. Nat. Commun. 8 (1), 682. https://doi.org/10.1038/s41467-017-00582-9 (Sep. 2017).
Teisseyre, H. et al. Homoepitaxial ZNO/ZNMGO laser structures and their properties. Phys. Status Solidi (A). 218 (1). https://doi.org/10.1002/pssa.202000344 (Sep. 2020).
Kim, S. et al. Understanding the light soaking effect of ZnMgO buffer in CIGS solar cells. Phys. Chem. Chem. Phys. 17 (29), 19222–19229. https://doi.org/10.1039/c5cp01758k (Jan. 2015).
Hariskos, D. et al. Apr., The Zn(S,O,OH)/ZnMgO buffer in thin-film Cu(In,Ga)(Se,S)2‐based solar cells part II: Magnetron sputtering of the ZnMgO buffer layer for in‐line co‐evaporated Cu(In,Ga)Se2 solar cells, Progress in Photovoltaics Research and Applications, vol. 17, no. 7, pp. 479–488, (2009). https://doi.org/10.1002/pip.897
Bahfir, M., Boumaour & Kechouane, M. Prospects of potential ZnMgO front layer in CZTS solar cells. Optik 169, 196–202. https://doi.org/10.1016/j.ijleo.2018.05.068 (May 2018).
Tong, H. et al. Influences of Mg concentration in ZnMgO film on energy band alignment at CIGSSe/Zn1-xMgxO interface and performances of CIGSSe solar cells, Solar Energy, vol. 246, pp. 216–223, Oct. (2022). https://doi.org/10.1016/j.solener.2022.09.039
Muchahary, D. & Maity, S. High-efficiency thin film ZnMgO/ZnO solar cell simulation approach: temperature dependency, BSF and efficient small signal analysis. Superlattices Microstruct. 109, 209–216. https://doi.org/10.1016/j.spmi.2017.05.012 (May 2017).
Algarni, H., Gueddim, A., Bouarissa, N., Khan, M. A. & Ziani, H. Crystal structure and electronic properties of wurtzite MgxZn1-xO: Ab initio study. Results Phys. 15, 102694. https://doi.org/10.1016/j.rinp.2019.102694 (Sep. 2019).
Loh, G. C., Teo, E. H. T. & Tay, B. K. Phononic and structural response to strain in wurtzite-gallium nitride nanowires. J. Appl. Phys. 111 (10). https://doi.org/10.1063/1.4716476 (May 2012).
Romanov, E., Baker, T. J., Nakamura, S. & Speck, J. S. Strain-induced polarization in wurtzite III-nitride semipolar layers. J. Appl. Phys. 100 (2). https://doi.org/10.1063/1.2218385 (Jul. 2006).
Dakua, P. K., Sreevedha, R., Sai, Y. A., Likitha, S., Jamalbe, S. & P. K., & Highly efficient CIGS-based solar cell with different back contact materials using SCAPS 1-D framework. J. Opt. 54 (4), 2275–2288 (2025).
Jose, F. P., Achary, S. R., Sukumaran, A. A. & Jayaraj, M. K. Effects of temperature and doping on aluminium doped ZnO thin film grown by spray pyrolysis, AIP Conference Proceedings, Jan. (2020). https://doi.org/10.1063/5.0009005
Li, D., Song, L., Chen, Y. & Huang, W. Modeling thin film solar cells: from organic to perovskite. Adv. Sci. 7 (1), 1901397. https://doi.org/10.1002/advs.201901397 (Nov. 2019).
Meher, S. R., Balakrishnan, L. & Alex, Z. C. Analysis of Cu2ZnSnS4/CdS based photovoltaic cell: A numerical simulation approach. Superlattices Microstruct. 100, 703–722. https://doi.org/10.1016/j.spmi.2016.10.028 (Oct. 2016).
Abdulmunem, O. M., Ali, M. J. M. & Hassan, E. S. Optical and structural characterization of aluminium doped zinc oxide thin films prepared by thermal evaporation system. Opt. Mater. 109, 110374. https://doi.org/10.1016/j.optmat.2020.110374 (Sep. 2020).
Xiang, Y. et al. Dec., Buried Interface Passivation with Butylammonium Methyl Sulfonate for High-Performance Inverted Wide-Band Gap Perovskite Solar Cells, ACS Applied Energy Materials, vol. 8, no. 24, pp. 18318–18326, (2025). https://doi.org/10.1021/acsaem.5c03201
Du, H. et al. Suppressing halide segregation via Dual-Anchoring strategy for 31.20% Perovskite/Silicon tandem solar cells. Adv. Energy Mater. 15 (47). https://doi.org/10.1002/aenm.202503565 (Sep. 2025).
Burgelman, M., Nollet, P. & Degrave, S. Modelling polycrystalline semiconductor solar cells. Thin Solid Films. 361–362. https://doi.org/10.1016/s0040-6090(99)00825-1 (Feb. 2000).
Jha, J., Meer, M., Ganguly, S. & Saha, D. Off-State degradation and recovery in Oxide/ALGAN/GAN heterointerfaces: importance of band offset, electron, and hole trapping. ACS Appl. Electron. Mater. 2 (7), 2071–2077. https://doi.org/10.1021/acsaelm.0c00322 (Jun. 2020).
Ding et al. Effect of the conduction band offset on interfacial recombination behavior of the planar perovskite solar cells. Nano Energy. 53, 17–26. https://doi.org/10.1016/j.nanoen.2018.08.031 (Aug. 2018).
Ma, J. et al. Parameter estimation of photovoltaic models via Cuckoo Search, Journal of Applied Mathematics, vol. pp. 1–8, Jan. 2013, (2013). https://doi.org/10.1155/2013/362619
Voyant et al. Machine learning methods for solar radiation forecasting: A review. Renew. Energy. 105, 569–582. https://doi.org/10.1016/j.renene.2016.12.095 (Jan. 2017).
Alhammadi, S., Park, H. & Kim, W. K. Optimization of intrinsic ZNO thickness in CU(In,GA)SE2-Based thin film solar cells, Materials, vol. 12, no. 9, p. 1365, Apr. (2019). https://doi.org/10.3390/ma12091365
Hamali, S. O. E. et al. Enhanced electrical and optical properties of room temperature deposited aluminium doped zinc oxide (AZO) thin films by excimer laser annealing. Opt. Lasers Eng. 80, 45–51. https://doi.org/10.1016/j.optlaseng.2015.12.010 (Jan. 2016).
Munkhbat, B., Wróbel, P., Antosiewicz, T. J. & Shegai, T. O. Optical Constants of Several Multilayer Transition Metal Dichalcogenides Measured by Spectroscopic Ellipsometry in the 300–1700 nm Range: High Index, Anisotropy, and Hyperbolicity, ACS Photonics, vol. 9, no. 7, pp. 2398–2407, Jun. (2022). https://doi.org/10.1021/acsphotonics.2c00433
Dhakal, T. P., Peng, C., Tobias, R. R., Dasharathy, R. & Westgate, C. R. Characterization of a CZTS thin film solar cell grown by sputtering method, Solar Energy, vol. 100, pp. 23–30, Dec. (2013). https://doi.org/10.1016/j.solener.2013.11.035
ElAnzeery, H. et al. Apr., Refractive index extraction and thickness optimization of Cu2ZnSnSe4thin film solar cells, Physica Status Solidi (A), vol. 212, no. 9, pp. 1984–1990, (2015). https://doi.org/10.1002/pssa.201431807
Ren, S. et al. Rapid thermal annealing on ZnMgO window layer for improved performance of CdTe solar cells. Sol. Energy Mater. Sol. Cells. 187, 97–103. https://doi.org/10.1016/j.solmat.2018.06.033 (Aug. 2018).
Jena, S., Tokas, R. B., Kamble, N. M., Thakur, S. & Sahoo, N. K. Optical properties and laser damage threshold of HfO2–SiO2 mixed composite thin films. Appl. Opt. 53 (5), 850. https://doi.org/10.1364/ao.53.000850 (Feb. 2014).
Jena, S. et al. Feb., Optical properties of electron beam evaporated ZrO2:10%SiO2 thin films: dependence on structure, Indian Journal of Physics, vol. 90, no. 8, pp. 951–957, (2016). https://doi.org/10.1007/s12648-016-0831-z
Jena, S., Tokas, R. B., Thakur, S. & Udupa, D. V. PRISA: a user-friendly software for determining refractive index, extinction co-efficient, dispersion energy, band gap, and thickness of semiconductor and dielectric thin films. Nano Express. 2 (1), 010008. https://doi.org/10.1088/2632-959x/abd967 (Jan. 2021).
Jena, S. et al. Influence of oxygen partial pressure on microstructure, optical properties, residual stress and laser induced damage threshold of amorphous HfO2 thin films. J. Alloys Compd. 771, 373–381. https://doi.org/10.1016/j.jallcom.2018.08.327 (Sep. 2018).
Bute, S. et al. Linear and non-linear optical properties of Boron carbide thin films. Appl. Surf. Sci. 608, 155101. https://doi.org/10.1016/j.apsusc.2022.155101 (Sep. 2022).
Cherouana & Labbani, R. Study of CZTS and CZTSSe solar cells for buffer layers selection. Appl. Surf. Sci. 424, 251–255. https://doi.org/10.1016/j.apsusc.2017.05.027 (May 2017).
Drummond, T. J. Work Functions of the transition Metals and Metal Silicides, Sandia National Labs., Albuquerque, NM (US), Feb. [Online]. (1999). Available: https://www.osti.gov/biblio/3597
Swain, S. K., Singh, S. & Sharma, S. K. Effect of temperature on analog/RF and linearity performance of InSb/Si heterojunction SOI TFET. Micro Nanostruct. 167, 207245. https://doi.org/10.1016/j.micrna.2022.207245 (May 2022).
Varshni, Y. P. Temperature dependence of the energy gap in semiconductors. Physica 34 (1), 149–154. https://doi.org/10.1016/0031-8914(67)90062-6 (Jan. 1967).
Green, M. A. Solar cells: operating principles, technology, and system applications. None Dec. 31, https://www.osti.gov/biblio/6051511 (1981).
Oubda, M. B., Kebre, F., Zougmoré, D., Njomo & Ouattara, F. Numerical simulation of CU(In,GA)SE2 solar cells performances. J. Energy Power Eng. 9 (12). https://doi.org/10.17265/1934-8975/2015.12.002 (Dec. 2015).
Yoshioka, T., Fujita, H., Kimura, Y., Hattori, Y. & Kitamura, M. Wide-range work function tuning in gold surfaces modified with fluorobenzenethiols toward application to organic thin-film transistors. Flex. Print. Electron. 5 (1), 014011. https://doi.org/10.1088/2058-8585/ab71e3 (Jan. 2020).
Benzetta, E., Abderrezek, M. & Djeghlal, M. E. Analysis of Cu2ZnSn(S,Se)4 (CZTSSe) Thin Film Solar Cells Performances with CZTSe Stacked Layer by Using SCAPS-1D, in Springer proceedings in energy, pp. 279–285. (2020). https://doi.org/10.1007/978-981-15-5444-5_35
Maklavani, S. E. & Mohammadnejad, S. The impact of the carrier concentration and recombination current on the p + pn CZTS thin film solar cells. Opt. Quant. Electron. 52 (6). https://doi.org/10.1007/s11082-020-02407-4 (May 2020).
Mora-Herrera, M., Pal & Santos-Cruz, J. Theoretical modelling and device structure engineering of kesterite solar cells to boost the conversion efficiency over 20%. Sol. Energy. 220, 316–330. https://doi.org/10.1016/j.solener.2021.03.056 (Apr. 2021).
Haddout, M. et al. Influence of composition ratio on the performances of kesterite solar cell with double CZTS layers—A numerical approach. Sol. Energy. 189, 491–502. https://doi.org/10.1016/j.solener.2019.07.098 (Aug. 2019).
Acknowledgements
We thank ELIS, University of Gent, for developingthe SCAPS tool for solar cell simulations.
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Pratap Kumar Dakua: Writing original draft, Supervision, Methodology, Investigation, Data curation, Conceptualization.Rohit Vikram Singh Bhadauria : Writing, review & editing, InvestigationDontabhaktuni Jayakumar : Review & editing.Rabinarayan Panda : Review & editingSukanta Kumar Swain : Writing, review & editing, ValidationVullanki Rajesh : Writing, review & editing, Conceptualisation.Suman Maloji : Supervision, Investigation, Conceptualization, Data curation, Methodology, Validation, VisualizationSiddharth Kumar : Data curation, Methodology, Validation.
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Dakua, P.K., Bhadauria, R.V.S., Jayakumar, D. et al. Numerical modeling of CZTS based heterostructured solar cell for high efficiency PV performance. Sci Rep (2026). https://doi.org/10.1038/s41598-026-37248-w
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DOI: https://doi.org/10.1038/s41598-026-37248-w
