Electron- phonon interaction and Electron Energy Loss Function of Spray Pyrolyzed Cu2CdSnS4  Thin Films at Different Substrate Temperatures

Authors

Keywords:

Cu₂CdSnS₄, Electron-phonon Interaction, Electron Energy Loss Function

Abstract

Cu₂CdSnS₄ (CCTS) thin films were successfully synthesized using the spray-pyrolysis method at substrate temperatures of 300 °C, 350 °C, and 400 °C. This study aimed to explore how deposition temperature impacts electron–phonon interaction, surface energy-loss function (SELF), and volume energy-loss function (VELF). X-ray diffraction (XRD) analysis showed a temperature-induced phase transition from the cernyite to the stannite structure, with crystallite size increasing from 32.5 nm to 48.3 nm. A decrease in dislocation density and microstrain, indicating improved crystallinity was noticed. Atomic Force Microscopy (AFM) analysis revealed that surface roughness increased with temperature, suggesting enhanced adatom mobility and grain coarsening. The optical absorption spectra from UV-Vis spectroscopy displayed a red-shift in the absorption edge as the temperature rose, resulting in a band gap reduction from 1.52 eV to 1.31 eV, while the refractive index slightly increased from 2.94 to 3.06. The Urbach energy also rose from 0.372 eV to 0.704 eV, indicating stronger disorder-induced tail states and enhanced electron–phonon coupling. We found that the calculated electron–phonon interaction strength increased from 5.03 eV to 8.10 eV with temperature, confirming that carrier–lattice coupling intensifies at higher growth temperatures. Both SELF and VELF increased systematically with temperature, reflecting improved crystallinity, enhanced dielectric resonance, and greater plasmonic activity. These results highlight the significant impact of substrate temperature on lattice dynamics and energy-loss mechanisms in CCTS thin films, which are crucial for optimizing absorber layers in next-generation thin-film solar cells.

Author Biographies

Michael B. Ochang

Industrial Physics,Senior Lecturer

Julius N. Tsaviv

Chemistry,  Chief Technologist

Peverga Rex Jubu

Industrial Physics, Senior Lecturer

Zendesha S. Mbalaha

Industrial Physics, Senior Lecturer

Bunmi J. Akeredolu

PHYSICS, SENIOR LECTURER

Adebayo T. Adepoju

INDUSTRIAL PHYSICS, LECTURER 1

Augustine A. McAsule

INDUSTRIAL PHYSICS LECTURER1

Yushamdan Yusof

PHYSICS , CHIEF TECHNOLOGIST  

Kalu Onyekachi

PHYSICS, SENIOR LECTURER

Dimensions

Abed, M. A., Bakr, N. A., & Al-Zanganawee, J. M. (2020). Structural, optical and electrical properties of Cu₂NiSnS₄ thin films deposited by chemical spray pyrolysis method. Chalcogenide Letters, 17(4), 179–186. https://doi.org/10.15251/CL.2020.174.179

Ahmad, A. A., Migdadi, A. B., Alsaad, A. M., Qattan, I. A., Al-Bataineh, Q. M., & Telfah, A. (2021). Computational and experimental characterizations of annealed Cu₂ZnSnS₄ thin films. Heliyon, 8(1), e08683. https://doi.org/10.1016/j.heliyon.2021.e08683

Ahmed, M. A., Bakr, N. A., & Kamil, A. A. (2019). Synthesis and characterization of chemically sprayed Cu₂CoSnS₄ thin films. Chalcogenide Letters, 16(5), 231–239.

Ahmed, H. J., Kamil, A. A., Habeeb, A. A., & Bakr, N. A. (2020). The influence of deposition temperature on the properties of chemically sprayed nanostructured Cu₂CdSnS₄ thin films. International Research Journal of Science and Technology, 1(2), 149–155. https://doi.org/10.46378/irjst.2020.010211

Al-Douri, Y., Odeh, A. A., Johan, M. R., Chowdhury, Z. Z., Rafique, R. F., Reshak, A. H., & Voon, C. H. (2018). Synthesis and characterization of Cu₂CdSnS₄ quaternary alloy nanostructures. International Journal of Electrochemical Science, 13, 6693–6707. https://doi.org/10.20964/2018.07.45

Alkauskas, A., Yan, Q., & Van de Walle, C. G. (2014). First-principles theory of nonradiative carrier capture via multiphonon emission. Physical Review B, 90(7), 075202. https://doi.org/10.1103/PhysRevB.90.075202

Baker, I. (2000). Recovery, recrystallization and grain growth in ordered alloys. Intermetallics, 8(9–11), 1183–1196. https://doi.org/10.1016/S0966-9795(00)00031-5

Bakr, N. A., Khodair, Z. T., & Abdul Hassan, S. M. (2015). Effect of substrate temperature on structural and optical properties of Cu₂ZnSnS₄ (CZTS) films prepared by chemical spray pyrolysis method. Research Journal of Chemical Sciences, 5(10), 51–61.

Bandoh, C. K., Nkrumah, I., Ampong, F. K., Nkum, R. K., & Boakye, F. (2021). Effect of annealing on the structure and optical properties of lead selenide and cadmium selenide thin film prepared by chemical bath deposition. Chalcogenide Letters, 18(2), 81–89.

Begum, A., Hussain, A., & Rahman, A. (2012). Effect of deposition temperature on the structural and optical properties of chemically prepared nanocrystalline lead selenide thin films. Beilstein Journal of Nanotechnology, 3, 438–443. https://doi.org/10.3762/bjnano.3.50

Bhushan, B. (2017). Scanning probe microscopy in nanoscience and nanotechnology (3rd ed.). Springer.

Bonalde, I., Medina, E., & Wasim, S. M. (2005). Temperature dependence of the Urbach energy in ordered defect compounds Cu-III₃-VI₅ and Cu-III₅-VI₈. Journal of Physics and Chemistry of Solids, 66(10), 1865–1867. https://doi.org/10.1016/j.jpcs.2005.10.002

Boriskina, S. V., Cooper, T. A., Zeng, L., Ni, G., Tong, J. K., Tsurimaki, Y., Huang, Y., Meroueh, L., Mahan, G., & Chen, G. (2017). Losses in plasmonics: From mitigating energy dissipation to embracing loss-enabled functionalities. Advances in Optics and Photonics, 9(4), 775–827. https://doi.org/10.1364/AOP.9.000775

Boutebakh, F. Z., Attaf, N., & Aida, M. S. (2025). Effect of growth temperature on the physical properties of kesterite Cu₂ZnSnS₄ (CZTS) thin films. Discover Materials, 5, Article 4. https://doi.org/10.1007/s43939-025-00179-w

Boyang, H., Li, Y., Wang, R., Zhu, W., He, Z., Sun, H., Meng, X., Huang, S., Song, Y., & Zhang, J. (2024). Viable strategy for suppressing antisite defects and band tailing states in solution-processed kesterite solar cells via IIIA incorporation: Case of aluminum. ACS Applied Energy Materials, 7(16), 7074–7084. https://doi.org/10.1021/acsaem.4c01475

Brahma, S., Lo, C.-Y., Chen, S.-C., Chu, H.-C., Hsu, C. H., & Huang, J.-L. (2024). Defect-induced crystal lattice disorder and its effect on the electron–phonon coupling in Fe-doped ZnO thin films. Journal of Physics and Chemistry of Solids, 190, 111999. https://doi.org/10.1016/j.jpcs.2024.111999

Caruso, F., Novko, D., & Draxl, C. (2018). Phonon-assisted damping of plasmons in three- and two-dimensional metals. Physical Review B, 97(20), 205118. https://doi.org/10.1103/PhysRevB.97.205118

Chen, L., Deng, H., Tao, J., Zhou, W., Sun, L., Yue, F., Yang, P., & Chu, J. (2015). Influence of annealing temperature on structural and optical properties of Cu₂MnSnS₄ thin films fabricated by sol-gel technique. Journal of Alloys and Compounds. https://doi.org/10.1016/j.jallcom.2015.03.225

Cullity, B. D., & Stock, S. R. (2014). Elements of X-ray diffraction (3rd ed.). Pearson Education Limited.

Daranfed, W., Aida, M. S., Attaf, N., Bougdira, J., & Rinnert, H. (2012). Cu₂ZnSnS₄ thin films deposition by ultrasonic spray pyrolysis. Journal of Alloys and Compounds, 542, 22–

Dizaj, M. H. (2025). Recombination mechanisms in perovskite materials: A theoretical and experimental perspective. Journal of Science and Engineering Elites. http://www.elitesjournal.ir

Enigochitra, A.S., P. Perumal, C. Sanjeeviraja, D. Deivamani, M. Boomashri. (2016).Influence of substrate temperature on structural and optical properties of ZnO thin films prepared by cost-effective chemical spray pyrolysis technique, Superlattices and Microstructures. 90:313-320, https://doi.org/10.1016/j.spmi.2015.10.026.

Giustino, F. (2017). Electron–phonon interactions from first principles. Reviews of Modern Physics, 89(1), 015003. https://doi.org/10.1103/RevModPhys.89.015003

Gunavathy, K.V., K. Tamilarasan, C. Rangasami, A.M.S. Arulanantham (2019). A review on growth optimization of spray pyrolyzed Cu2ZnSnS4 chalcogenide absorber thin film, International Journal of Energy Research .https://doi.org/10.1002/er.4693.

Handa, T., Aharen, T., Wakamiya, A., & Kanemitsu, Y. (2018). Radiative recombination and electron–phonon coupling in lead-free CH₃NH₃SnI₃ perovskite thin films. Physical Review Materials, 2(7), 075402. https://doi.org/10.1103/PhysRevMaterials.2.075402

Hao Guan, Jingchuan Zhao , Xu Wang , Fangli Yu (2013) Cu2CdSnS4 Thin Film Prepared by a Simple Solution Method. Chalcogenide Letters Vol. 10, No. 10, October 2013, P. 367 – 372.

Henry, J, Mohanraj, K.,. Sivakumar, G .(2016).Electrical and optical properties of CZTS thin films prepared by SILAR method, Journal of Asian Ceramic Societies, 4(1): 81-84. https://doi.org/10.1016/j.jascer.2015.12.003

Hossain, M. D. S., Kabir, H., Rahman, M. M., Hasan, K., Bashar, M. S., Rahman, M., Gafur, M. A., Islam, S. H., Amri, A., Jiang, Z. T., Altarawneh, M., & Dlugogorskii, B. Z. (2016). Understanding the shrinkage of optical absorption edges of nanostructured Cd–Zn sulphide films for photothermal applications. Applied Surface Science, 392, 1038–1046. https://doi.org/10.1016/j.apsusc.2016.09.095

Ibraheam, A. S., Al-Douri, Y., Al-Hazeem, N. Z., Hashim, U., Prakash, D., & Verma, K. D. (2016). Effect of cadmium concentration on structural, optical, and electrical properties of Cu₂Zn₁₋ₓCdₓSnS₄ quinternary alloy nanofibres synthesized by electrospinning technique. Journal of Nanomaterials, 2016, Article 7314714. https://doi.org/10.1155/2016/7314714

Islam, M. (2013). High quality 1 μm thick CdTe absorber layers grown by magnetron sputtering for solar cell application. Current Applied Physics, 13(1), 115–121. https://doi.org/10.1016/j.cap.2013.02.015

Joel, J., Mahony, T. S., Bozyigit, D., Sponseller, M., Holovsky, J., Bawendi, M. G., & Bulovic, V. (2017). Radiative efficiency limit with band tailing exceeds 30% for quantum dot solar cells. ACS Energy Letters, 2(11), 2616–2624. https://doi.org/10.1021/acsenergylett.7b00923

Khalate, S. A., Kate, R. S., Kim, J. H., Pawar, S. M., & Deokate, R. J. (2017). Effect of deposition temperature on the properties of Cu₂ZnSnS₄ (CZTS) thin films. Superlattices and Microstructures, 103, 335–342. https://doi.org/10.1016/j.spmi.2017.02.003

Kumar, Y. B. K., Bhaskar, P. U., Babu, G. S., & Raja, V. S. (2010). Effect of copper salt and thiourea concentrations on the formation of Cu₂ZnSnS₄ thin films by spray pyrolysis. physica status solidi (a), 207(1), 149–156. https://doi.org/10.1002/pssa.200925194

Kumar, M. S., Mohanta, K., & Batabyal, S. K. (2017). Solution processed Cu₂CdSnS₄ as a low-cost inorganic hole transport material for polymer solar cells. Solar Energy Materials and Solar Cells, 161, 157–161. https://doi.org/10.1016/j.solmat.2016.11.028

Lehmann, D., Seidel, F., & Zahn, D. R. (2014). Thin films with high surface roughness: Thickness and dielectric function analysis using spectroscopic ellipsometry. SpringerPlus, 3, 82. https://doi.org/10.1186/2193-1801-3-82

Liu, X., Feng, Y., Cui, H., Liu, F., Hao, X., Conibeer, G., Mitzi, D. B., & Green, M. A. (2016). The current status and future prospects of kesterite solar cells: A brief review. Progress in Photovoltaics: Research and Applications, 24(6), 879–898. https://doi.org/10.1002/pip.2741

Mabvuer, F. T., Nya, F. T., & Kenfack, G. M. D. (2022). Improving the absorption spectrum and performance of CIGS solar cells by optimizing the stepped band gap profile of the multilayer absorber. Solar Energy, 240, 193–200. https://doi.org/10.1016/j.solener.2022.05.037

Mahato, S., Patel, M., & Bhattacharya, P. (2017). Influence of deposition temperature on structural, optical and dielectric properties of CZTS thin films. Materials Research Bulletin, 95, 410–418. https://doi.org/10.1016/j.materresbull.2017.08.028

Makhnovets, G. V., Myronchuk, G. L., Piskach, L. V., Vidrynskyi, B. V., & Kevshyn, A. H. (2018). Study of optical absorption in TlGaSe₂:Zn²⁺ single crystals. Ukrainian Journal of Physical Optics, 19(1), 49–59. https://doi.org/10.3116/16091833/19/1/49/2018

Ilkhani, M., & Dejam, L. (2021). Structural and optical properties of ZnO and Ni:ZnO thin films: The trace of post-annealing. Journal of Materials Science: Materials in Electronics, 32, 3460–3474. https://doi.org/10.1007/s10854-020-05092-x

Mkhoyan, K. A., Babinec, T., Maccagnano, S. E., Kirkland, E. J., & Silcox, J. (2007). Separation of bulk and surface losses in low-loss EELS. Ultramicroscopy, 107(4–5), 345–355. https://doi.org/10.1016/j.ultramic.2006.09.003

Mohamed, J. R., Sanjeeviraja, C., & Amalraj, L. (2016). Influence of substrate temperature on physical properties of (111) oriented CdIn₂S₄ thin films by nebulized spray pyrolysis technique. Journal of Asian Ceramic Societies, 4(2), 191–200. https://doi.org/10.1016/j.jascer.2016.03.002

Monserrat, B., Park, J.-S., Kim, S., & Walsh, A. (2018). Role of electron–phonon coupling and thermal expansion on band gaps, carrier mobility, and interfacial offsets in kesterite thin-film solar cells. Applied Physics Letters, 112(19), 193903. https://doi.org/10.1063/1.5028186

Nguyen-Truong, H. T. (2014). Energy-loss function including damping and prediction of plasmon lifetime. Journal of Electron Spectroscopy and Related Phenomena, 196, 23–29. https://doi.org/10.1016/j.elspec.2014.03.010

Pishdadian, S., & Ghaleno, A. M. S. (2013). Influences of annealing temperature on the optical and structural properties of manganese oxide thin film by Zn doping from sol-gel technique. Acta Physica Polonica A, 123(4), 741–745. https://doi.org/10.12693/APhysPolA.123.741

Rambadey, O. V., Kumar, A., Sati, A., & Sagdeo, P. R. (2021). Exploring the interrelation between Urbach energy and dielectric constant in Hf-substituted BaTiO₃. ACS Omega, 6(47), 32231–32238. https://doi.org/10.1021/acsomega.1c05057

Ren, Y. I. (2017). Annealing of Cu₂ZnSn(S,Se)₄ thin films: A study of secondary compounds and their effects on solar cells (Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology No. 1476). Uppsala University. ISSN 1651-6214. urn:nbn:se:uu:diva-314975

Rey, G., Larramona, G., Bourdais, S., Choné, C., Delatouche, B., Jacob, A., Dennler, G., & Siebentritt, S. (2018). On the origin of band-tails in kesterite. Solar Energy Materials and Solar Cells, 179, 142–151. https://doi.org/10.1016/j.solmat.2017.11.005

Rocca, M., Lindau, I., & Onellion, M. (1995). Energy-loss functions and surface plasmons in semiconductors. Surface Science Reports, 22(1), 1–54. https://doi.org/10.1016/0167-5729(94)00006-7

Rondiya, S. R., Jadhav, Y. A., Živković, A., Jathar, S. B., Rahane, G. K., Cross, R. W., Rokade, A. V., Devan, R. S., Kolekar, S., Hoye, R. L. Z., de Leeuw, N. H., Jadkar, S. R., & Dzade, N. Y. (2022). Solution-processed Cd-substituted CZTS nanocrystals for sensitized liquid junction solar cells. Journal of Alloys and Compounds, 890, 161575. https://doi.org/10.1016/j.jallcom.2021.161575

Aanchal, S., Kumar, A., Mishra, V., Warshi, K., Pokhriyal, P., Sagdeo, A., & Sagdeo, P. R. (2021). Temperature-dependent dielectric loss in BaTiO₃: Competition between tunnelling probability and electron–phonon interaction. Materials Chemistry and Physics, 257, 123792. https://doi.org/10.1016/j.matchemphys.2020.123792

Rawat, S., Gupta, R., & Gohri, S. (2023). Performance assessment of CIGS solar cell with different CIGS grading profile. Materials Today: Proceedings. https://doi.org/10.1016/j.matpr.2023.03.356

Wang, S., Peng, Y., Li, L., Zhou, Z., Liu, Z., Zhou, S., & Yao, M. (2022). Impact of loss mechanisms on performances of perovskite solar cells. Physica B: Condensed Matter, 647, 414363. https://doi.org/10.1016/j.physb.2022.414363

Skoog, D.A., Holler, F.J. and Crouch, S.R. (2017) Principal of Instrumental Analysis. 7th Edition, Sunder College Publisher, New York.

Schorr, S., Gurieva, G., Guc, M., Dimitrievska, M., Pérez-Rodríguez, A., Izquierdo-Roca, V., Schnohr, C., Merino, J. M., Kim, J., & Jo, W. (2020). Point defects, compositional fluctuations, and secondary phases in non-stoichiometric kesterites. Journal of Physics: Energy, 2(1), Article 012002. https://doi.org/10.1088/2515-7655/ab4a25

Sun, K., Huang, J., Li, J., Yan, C., & Hao, X. (2023). Recent progress in defect engineering for kesterite solar cells. Science China Physics, Mechanics & Astronomy, 66, Article 217302. https://doi.org/10.1007/s11433-022-1939-6

Suresh, K. M., Sreejith, P., Athimotlu, R. R., Mohamed, S., & Sudip, K. B. (2020). Barium (Ba) substitution in kesterite Cu₂ZnSnS₄: Cu₂Zn₁₋ₓBaₓSnS₄ (CZBTS) quinary alloy thin films for efficient solar energy harvesting. Crystal Growth & Design. (Please verify volume, issue, page numbers, and DOI, as the DOI provided appears inconsistent with the journal title.)

Surgina, G. D., Nevolin, V. N., Sipaylo, I. P., Teterin, P. E., Medvedeva, S. S., Lebedinsky, Y. Y., & Zenkevich, A. V. (2015). Effect of annealing on structural and optical properties of Cu₂ZnSnS₄ thin films grown by pulsed laser deposition. Thin Solid Films. https://doi.org/10.1016/j.tsf.2015.10.014

Savariraj, D., Kim, H.-J., Karuppanan, S., & Prabakar, K. (2017). Phase transformation and evolution of localized surface plasmon resonance in Cu₂–xS thin films deposited at 60 °C. The Journal of Physical Chemistry C, 121(45), 25440–25446. https://doi.org/10.1021/acs.jpcc.7b07332

Tiwari, D., Chaudhuri, T. K., Shripathi, T., Deshpande, U., & Sathe, V. G. (2014). Structural and optical properties of layer-by-layer solution deposited Cu₂SnS₃ films. Journal of Materials Science: Materials in Electronics, 25, 3687–3694. https://doi.org/10.1007/s10854-014-2076-y

Tombak A, Kilicoglu T, Ocak YS, (2019).Solar cells fabricated by spray pyrolysis deposited Cu2CdSnS4 thin films, Renewable Energy, doi: https://doi.org/10.1016/ j.renene.2019.07.057

Ungár, T., and Borbély, A. (1996). The effect of dislocation contrast on X-ray line broadening: A new approach to line profile analysis. Applied Physics Letters, 69(21), 3173–3175. https://doi.org/10.1063/1.117951

Vettumperumal, R. S. Kalyanaraman, B. Santoshkumar, R. Thangavel, (2015). Estimation of Electron-Phonon coupling and Urbach Energy in Group I elements doped ZnO Nanoparticles and Thin Films by Sol-Gel Method, Materials Research Bulletin http://dx.doi.org/10.1016/j.materresbull.2016.01.015

Yang, X., Qin, X., Yan, W., Zhang, C., Zhang, D., & Guo, B. (2022). Electronic Structure and Optical Properties of Cu2ZnSnS4 under Stress Effect. Crystals, 12(10), 1454. https://doi.org/10.3390/cryst12101454

Ye-Jin K, Levi D. Palmer, Wonseok L, Nicholas J. Heller, Scott K. C. (2023). Using electron energy-loss spectroscopy to measure nanoscale electronic and vibrational dynamics in a TEM. Journal of Chemical Physics. https://doi.org/10.1063/5.0147356

Zaki, M.-Y., Sava, F., Buruiana, A.-T., Simandan, I.-D., Becherescu, N., Galca, A.-C., Mihai, C., & Velea, A. (2021). Synthesis and Characterization of Cu₂ZnSnS₄ Thin Films Obtained by Combined Magnetron Sputtering and Pulsed Laser Deposition. Nanomaterials, 11(9), 2403. https://doi.org/10.3390/nano11092403

Zhang, Q., Deng, H., Chen, L., Tao, J., Yu, J., Yang, P., & Chu, J. (2017). Effects of sulfurization temperature on the structural and optical properties of Cu₂CdSnS₄ thin films prepared by direct liquid method. Materials Letters, 193, 206–209. https://doi.org/10.1016/j.matlet.2017.02.002

Zhenzhu Z, Mulin S Fang X, Xuefei W, Zachary F, Zongming H, Junyao G, Honghe D, Pengju T, Chengjian Y, Yuqian Y, Nikita A. Emelianov, Lyubov A. Frolova, Zhengguo Xiao, Pavel A. Troshin, Thomas P. Russell, Junfa Zhu, Yu Li and Qin Hu (2024). Enhanced charge carrier extraction and transport with interface modification for efficient tin-based perovskite solar cells. J. Mater. Chem. A, 2025,13, 409-417. https://doi.org/10.1039/D4TA06046F

Zhu J., Tang, M, B. He, W. Zhang, X. Li, Z. Gong, H. Chen, Y. Duan and Q. Tang(2020). Improved charge extraction through interface engineering for 10.12% efficiency and stable CsPbBr3 perovskite solar cells. J. Mater. Chem. A, https://doi.org/10.1039/D0TA08675D

Published

2026-06-23

How to Cite

Electron- phonon interaction and Electron Energy Loss Function of Spray Pyrolyzed Cu2CdSnS4  Thin Films at Different Substrate Temperatures. (2026). Nigerian Journal of Applied Physics, 2(2), 75-89. https://doi.org/10.62292/njap-v2i2-2026-40

Issue

Vol. 2 No. 2 (2026): Nigerian Journal of Applied Physics - Vol. 2 No. 2

Section

Articles
Copyright & Licensing

Copyright (c) 2026 Michael B. Ochang, Julius N. Tsaviv, Peverga Rex Jubu, Zendesha S. Mbalaha, Bunmi J. Akeredolu, Adebayo T. Adepoju, Ngutor S. Akiiga, Augustine A. McAsule, Yushamdan Yusof, Kalu Onyekachi

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

How to Cite

Electron- phonon interaction and Electron Energy Loss Function of Spray Pyrolyzed Cu2CdSnS4  Thin Films at Different Substrate Temperatures. (2026). Nigerian Journal of Applied Physics, 2(2), 75-89. https://doi.org/10.62292/njap-v2i2-2026-40