Enhancement of Optical, Structural, and Solid-State Properties of Copper Zinc Tin Sulfide Thin Films Using Cetyltrimethyl Ammonium Bromide via Low-Cost Chemical Bath Deposition for Solar Energy Harvesting

Abstract:

The use of innovative engineering materials, such as conducting polymers or surfactants, in thin films has shifted the focus of solar cell production from rare elements towards low-cost, abundant, and non-toxic alternatives. This research aims to synthesize and characterize an enhanced, low-cost Copper Zinc Tin Sulfide (CZTS) material for solar cell applications using Cetyltrimethylammonium Bromide (CTAB) as a surfactant through the chemical bath deposition (CBD) process. The precursor solution for film growth was prepared from the sources of copper sulfate, zinc sulfate, tin chloride, thiacetamides, and CTAB in a volume ratio of 2:2:2:2:1. CTAB was employed as a capping agent to improve the optical, morphological, and solid-state properties of the CZTS films. Following deposition, the samples were annealed for one hour period at a temperature of 200°C. The deposited films were analyzed using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Raman Spectroscopy. SEM analysis revealed a dense structure with extremely small nanopores and compacted grains, suggesting that the presence of CTAB in the film enhanced the morphology and improved the conductivity of the CZTS film. Optical properties are assessed using a 756S UV-VIS-NIR Spectrophotometer, and the results demonstrated low absorbance, reflectance, and transmittance. Bandgap values of 1.34 eV, 1.38 eV, and 1.48 eV were obtained, closely matching the 1.45 eV value of pure CZTS. The addition of the polymer significantly increased electrical conductivity, as evidenced by the well-formed particle structure observed in XRD and SEM images.

• Periodical: Journal of Metastable and Nanocrystalline Materials (Volume 42)
• Pages: 9-26
• DOI: https://doi.org/10.4028/p-eRhcR4
• Online since: November 2025
• Authors: Nnabuike Ezukwoke*, Edward Chukwudi Anoliefo, Mkpamdi Eke, Edmund Nnabueze Ajimah, Jonas Nnaemeka Onah
• Keywords: Bandgap, Conducting Polymers, Electron-Microscopy, Nano-Particles, P-N Junction Mechanism

References

[1] Z. Ahmad et al " Copper Zinc Tin Sulfide thin film solar cells: an overview" Elsevier photovoltaic beyond silicon innovation materials engineering 2024, page 303-322.

DOI: 10.1016/b978-0-323-90188-8.00009-9

[2] S.Chander et al, "Nontoxic and earth-abundant Cu2ZnSnS4 (CZTS) thin film solar cells: A review on high throughput processed methods," Elsevier Materials Today Sustainability, Volume 25, March 2024, 100662.

DOI: 10.1016/j.mtsust.2023.100662

[3] C. M. Nkinyam et al, "Insight into organic photovoltaic cell: prospects and challenges," Elsevier Unconditional Resources Volume 5, January 2025, 10012, https://doi.org/10.1016/j.uncres, 2024.100121.

[4] S. Ho et al "Recent Advances in the Development of Thin Films for Solar Cell Application" International Journal of Engineering Trend and Technology ISSN, 2231-5381, Volume 73, Issue 2, February 2025, https://doi.org/10.14445/22315381/ IJETTV7312p123.

[5] H. Kang et al, "Crystalline silicon vs amorphous silicon: the significance of structural differences in photovoltaic application," IOP Publishing 2020 2nd International Conference on Resources and Environmental Research.

DOI: 10.1088/1755-1315/726/1/012001

[6] A. Boundouma et al, "Electrodeposition synthesis of CZTS thin films as a promising material for photovoltaic cells: Fundamentals, methods and future prospects," Elsevier Materials Today Sustainability, Volume 28, December 2024. .101018. https:doi.org/10.1016/j.mtsust.2024 101018

DOI: 10.1016/j.mtsust.2024.101018

[7] D. Ali et al, "Optical Evaluation of the Rear Contact of Crystalline Silicon Solar Cells by Coupled Electromagnetic and Statistical Ray Optics Modeling," IEEE Journal of Photovoltaics.

DOI: 10.1109/jphotov.2017.2663658

[8] G Ghazi et al, 'Analytical modeling study of CZTSthin films solar cell for high High Efficiency performance'' Iternational informative and Engineering Technology Association Vol34 No5, October 2024, PP667-672 https://iieta'org/journals/rema.

[9] F.A. Jhuma et al, 'Towards high-efficiency CZTS solar cell through buffer layer optimization', Materials for Renewable and Sustainable Energy (2019) 8:6.

DOI: 10.1007/s40243-019-0144-1

[10] L. Ding et al, 'Polymer semiconductor: Synthesis, Processing and applications'', American Chemical Society Vol 123 Issue 12 2023. doi:org/.

DOI: 10.1021/acs.chemrev.2c00696

[11] N. Jahan et al, "Design and simulation of highly efficient CZTS/CZTSE-based thin films solar cell," Heliyon Elsevier, October 2024, https: //doi.org/101016/j.heliyon.2024 e39903.

DOI: 10.1016/j.heliyon.2024.e39903

[12] S. Sarsic, "The Physical Properties of CZTS Absorber Layer for Solar Cell Application", International Journal of Science, Technology and Design, ISTD, Vol 2, No.1, 2021.: 2757-8127, http://uludag.edu.tr/istd.

[13] W. Hou, Y. et al "The Applications of Polymers in Solar Cells: A Review," www.mdpi.com/journal/polymer,doi:10.3390/polym11010143, p.1–5, Polymers 2019.

[14] A. H. Almawgari et al, "Optical absorption performance of CZTS/ZnO thin films solar cells comprising anti-reflecting coating of texturing configuration" Royal Society of Chemistry RSC, 2023, 13, 31554-31568, October 2023.

DOI: 10.1039/D3RA05056D

[15] A. Luceño-s and A. Mar, "Materials for Photovoltaics: State of Art and Recent Developments," International Journal of Molecular Sciences Review, Int. J. Mol. Sci. 2019, 20, 976, doi:10.3390/ijms20040976 2019, 20, 976.

DOI: 10.3390/ijms20040976

[16] M.N. Tousif, S. Mohammad, A.A. Ferdous, and M.A. Hoque, "Investigation of Different Materials as Buffer Layer in CZTS Solar Cells Using SCAPS," Journal of Clean Energy Technologies, doi:10.18178/jocet.2018.6.4.477, vol. 6, No. 4, July 2018.

DOI: 10.18178/jocet.2018.6.4.477

[17] A. Kowsar, M. Rahaman, S. Islam, A. Y. Imam, and S. Chandra, "Effect of Annealing Atmosphere on Structural and Optical Properties of CZTS Thin Films Prepared By Spin-Coating," Bangladesh J. Sci. Ind. Res. 53(1), 13-20, 2018.

DOI: 10.3329/bjsir.v53i1.35905

[18] M. Khushaim et al, ''Study of kesterite Cu2ZnSnS4 (CZTS) thin films deposited by spray technique for photovoltaic Applications," Journal of Taibah University For Science 2021, Vol. 15, No. 1, 329–339.

DOI: 10.1080/16583655.2021.1978809

[19] V. Mahalakshmi et al, "Deposition of quaternary Cu2ZnSnS4 (CZTS) thin film by chemical bath deposition method for solar cell application," Journal of Optoelectronics and Advanced Materials Vol. 22, No. 11-12, November –December 2020, p.619 – 622.

DOI: 10.70729/ijser172084

[20] P. Prabeesh et al, "Fabrication of kesterite absorber films by spray pyrolysis: Effect of annealing temperature on the phase formation," Advanced Materials Proceedings2017, 2(1), 46-50.

DOI: 10.5185/amp.2017/111

[21] J. Sawant, "Photo-electrochemical Properties of Spray Deposited Cu2ZnSnS4 Photo-electrode: Enhancement in Photo-conversion Efficiency with Film Thickness" ES Energy & Environment, 2020, 10, 73-79.

DOI: 10.30919/esee8c933

[22] N Bakr "Deposition and Characterization of Cu2ZnSnS4 Thin Films for Solar Cell Applications," International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 6 (2018) pp.3379-3388, Research India Publications, http://www.ripublication.com.

[23] K. Mukhopadhyay et al, "Deposition of quaternary Cu2ZnSnS4 (CZTS) thin film by chemical bath deposition method for solar cell application," Journal of Optoelectronics and Advanced Materials vol. 22, no. 11-12, November – December 2020, p.619 – 622.

DOI: 10.70729/ijser172084

[24] H. Borate et al, "Single-step Electrochemical Deposition of CZTS Thin Films with Enhanced Photo-activity," ES Mater. Manuf., 2021, 11, 30-39.

DOI: 10.30919/esmm5f934

[25] M. Rahman et al, "Optical and Structural Study of the CZTS (Cu2ZnSnS4) Thin Film for Solar Cell Derived from the Chloride-Based sol-gel Precursor Solution," Dhaka Univ. J. Sci. 70(1): 1-7, 2022 (January).

DOI: 10.3329/dujs.v70i1.60374

[26] B. Bade et al, "Investigations of the structural, optoelectronic and band alignment properties of Cu2ZnSnS4prepared by hot-injection method towards low-cost photovoltaic applications," Elsevier Journal of Alloys and Compounds 854 (2021) 157093, http://www.elsevier.com/locate/jalcom.

DOI: 10.1016/j.jallcom.2020.157093

[27] M. C. Benachour et al, "Annealing duration influence on dip-coated CZTS thin films properties obtained by sol-gel method."Optik - International Journal for Light and Electron Optics 187 (2019) 1–8.

DOI: 10.1016/j.ijleo.2019.05.015

[28] M. Sultana, "Fabrication of Cu2 ZnSnS4 (CZTS) thin films by ultrasonic spray pyrolysis at a low substrate temperature and effect of tin concentration on the characteristics of the CZTS thin films, "Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh.

DOI: 10.3329/bjsir.v57i1.58894

[29] N. Ezukwoke et al, "The effect of polyvinyl alcohol (PVA) on the optical, electrical and solid state properties of copper zinc tin sulfide (CZTS) deposited by sensitive spray pyrolysis (SSP)" Journal of the Indian Chemical Society, www.journals.elsevier.com/journal-of-the-indian-chemical-society

DOI: 10.1016/j.jics.2022.100857

[30] M. Cumbajín, P. Sánchez, M. Núñez, and C. Gordón, "Energy Harvesting System with Solar Panels to Supply Low Power Electronic Devices," IOP Conf. Ser. Earth Environ. Sci., vol. 1141, no. 1, 2023.

DOI: 10.1088/1755-1315/1141/1/012008

[31] D. Hao et al., "Solar energy harvesting technologies for PV self-powered applications: A comprehensive review," Renew. Energy, vol. 188, p.678–697, 2022.

DOI: 10.1016/j.renene.2022.02.066

[32] K. Malek et al., "Design and implementation of sustainable solar energy harvesting for low-cost remote sensors equipped with real-time monitoring systems," J. Infrastruct. Intell. Resil., vol. 2, no. 3, p.100051, 2023.

DOI: 10.1016/j.iintel.2023.100051

[33] S. Sarang, G.M. Stojanovic, M. Drieberg, S. Stankovski, K. Bingi, and V. Jeoti, "Machine Learning Prediction Based Adaptive Duty Cycle MAC Protocol for Solar Energy Harvesting Wireless Sensor Networks," IEEE Access, vol. 11, no. February, p.17536–17554, 2023.

DOI: 10.1109/ACCESS.2023.3246108

[34] D. Ursic, M. Pirc, M. Jost, M. Topic, and M. Jankovec, "Ultra-low-power indoor light harvesting and solar cell characterisation system," IEEE Access, vol. 12, no. September, 2024.

DOI: 10.1109/ACCESS.2024.3492319

[35] D. Wu, Z. Lu, J. Tan, T. Lin, Y. Liu, and K. Wang, "A Feedback Analytic Algorithm for Maximal Solar Energy Harvesting of InP Stepped Nanocylinders," IEEE Photonics J., vol. 16, no. 1, p.1–9, 2024.

DOI: 10.1109/JPHOT.2024.3353787