Correlation between silver alloying, post-deposition treatment, and photovoltaic parameters in chalcopyrite thin film solar cells produced at low temperature

Öz

In this study, the correlation between silver alloying, post-deposition treatment, and photovoltaic parameters in chalcopyrite thin film solar cells produced by multi source physical vapour deposition chamber at low temperature was investigated by scanning electron microscope, energy dispersive X-ray spectroscopy, glow discharge optical emission spectroscopy, current density-voltage, and external quantum efficiency measurement techniques. It is found that, the silver alloying increased the average grain size in samples with and without NaF post-deposition treatment while NaF post-deposition treatment did not have a significant effect on average grain size. Silver alloying did not have an important effect on open circuit voltage without NaF post-deposition treatment application. However, NaF post-deposition treatment increased the open circuit voltage value of the reference sample from 598 mV to 628 mV. Moreover, the application of both silver alloying and NaF post-deposition treatment resulted the best open circuit voltage with 658 mV. Both the application of silver alloying and NaF post-deposition treatment separately and the application of both together improved the fill factor and short circuit current density values. The distributions of gallium and indium in the samples became more homogeneous and the solubility of the sodium in the structure was increased after silver alloying. Post-deposition treatment decreased the open circuit voltage deficit and both NaF post-deposition treatment and silver alloying improved the solar cell efficiency. The best efficiency of 16.2% was obtained in the sample with silver alloying and the NaF post-deposition treatment.

Anahtar Kelimeler

• Silver alloying
• Solar cell
• Low temperature
• Post-deposition treatment

Kaynakça

1. [1] Conibeer GJ, Willoughby A. Solar cell materials: Developing technologies. John Wiley and Sons Ltd, England, 2014.
2. [2] Lee TD, Ebong AU. A review of thin film solar cell technologies and challenges. Renewable and Sustainable Energy Reviews 2017; 70: 1286-1297.
3. [3] Jäger-Waldau A. Status and perspectives of thin film photovoltaics - Thin film solar cells: Current status and future trends. Nova Science Publishers Inc, New York, US, 2010.
4. [4] Poortmans J, Arkhipov V. Thin film solar cells: Fabrication, characterization, and applications. John Wiley & Sons, West Sussex, England, 2006.
5. [5] Minoura S, Kodera K, Maekawa T, Miyazaki K, Niki S, Fujiwara H. Dielectric function of Cu(In, Ga)Se2-based polycrystalline materials. Journal of Applied Physics 2013; 113: 063505.
6. [6] Wei SH, Zhang SB, Zunger A. Effects of Ga addition to CuInSe2 on its electronic, structural, and defect properties. Applied Physics Letters 1998; 72: 3199-3201.
7. [7] Naghavi N, Mollica F, Goffard J, Posada J, Duchatelet A, Jubault M, Donsanti F, Cattoni A, Collin S, Grand PP, Greffet JJ, Lincot D. Ultrathin Cu(In,Ga)Se2 based solar cells. Thin Solid Films 2017; 633: 55-60.
8. [8] Bulbul S, Ertugrul G, Arli F. Investigation of usage potentials of global energy systems. International Advanced Researches and Engineering Journal 2018; 2(1): 58-67.

9. [9] Dumrul H, Arli F, Taskesen E. Dust effect on PV modules: Its cleaning methods. In book: Innovative research in engineering 2023; 183-200. Duvar Publishing.
10. [10] Bhandari KP, Collier JM, Ellingson RJ, Apul DS. Energy payback time (EPBT) and energy return on energy invested (EROI) of solar photovoltaic systems: A systematic review and meta-analysis. Renewable and Sustainable Energy Reviews 2015; 47: 133-141.
11. [11] Ağca S, Çankaya G, Sonmezoglu S. Impact of tellurium as an anion dopant on the photovoltaic performance of wide-bandgap Cu(In,Ga)Se2 thin-film solar cells with rubidium fluoride post-deposition treatment. Frontiers in Energy Research 2023; 11: 1215712.
12. [12] Ağca S, Çankaya G. Photovoltaic properties of Cu(In,Ga)(Se,Te)2 thin film solar cells with different tellurium amounts and a copper-poor stoichiometry. International Journal of Energy Studies 2023; 8(4): 849-858.
13. [13] Ağca S, Çankaya G. Effect of gallium content on diode characteristics and solar cell parameters of Cu(In1-xGax)(Se0.98Te0.02)2 thin film solar cells produced by three-stage co-evaporation at low temperature. Gazi University Journal of Science Part C: Design and Technology 2023; 11(4): 1108-1115.
14. [14] Boyle JH, McCandless BE, Shafarman WN, Birkmire RW. Structural and optical properties of (Ag,Cu)(In,Ga)Se2 polycrystalline thin film alloys. Journal of Applied Physics 2014; 115: 223504.
15. [15] Erslev PT, Lee J, Hanket GM, Shafarman WN, Cohen JD. The Electronic structure of Cu(In1−xGax)Se2 alloyed with silver. Thin Solid Films 2011; 519: 7296-7299.
16. [16] Lu HT, Ou CY, Lu CH. (Ag,Cu)(In,Ga)Se2 Thin films fabricated on flexible substrates via non-vacuum process. Journal of Materials Science: Materials in Electronics 2018; 29: 1614-1622.
17. [17] Erslev PT, Hanket GM, Shafarman WN, Cohen JD. Characterizing the effects of silver alloying in chalcopyrite CIGS solar cells with junction capacitance methods. Materials Research Society Symposium Proceedings 2009; 1165: 107.
18. [18] Shafarman WN, Thompson C, Boyle J, Hanket G, Erslev P, Cohen JD. Device characterization of (AgCu)(InGa)Se2 solar cells. 35th IEEE PhotovoltaicSpecialists Conference 2010; 11625968: 325-329.
19. [19] Ağca S. New studies on chalcopyrite thin film solar cells: Silver alloying. International Journal of Engineering Research and Development 2024; 16(1): 106-116.
20. [20] Wang C, Zhuang D, Zhao M, Li Y, Dong L, Wang H, Wei J, Gong Q. Effect of silver doping on properties of Cu(In,Ga)Se2 films prepared by CuInGa precursors. Journal of Energy Chemistry 2022; 66: 218-225.
21. [21] Edoff M, Jarmar T, Nilsson NS, Wallin E, Högstrom D, Stolt O, Lundberg O, Shafarman WN, Stolt L. High Voc in (Cu,Ag)(In,Ga)Se2 solar cells. IEEE Journal of Photovoltaics 2017; 7(6): 1789-1794.
22. [22] Helder T, Kanevce A, Zinsser M, Gutzler R, Paetel S, Hempel W, Friedlmeier TM, Powalla M. How small changes make a difference: Influence of low silver contents on the effect of RbF-PDT in CIGS solar cells. Progress in Photovoltaics: Research and Applications 2022; 31(12): 1205-1214.
23. [23] Valdes NH, Lee JW, Shafarman WN. Ag alloying and KF treatment effects on low bandgap CIGS solar cells. IEEE 7th World Conference on Photovoltaic Energy Conversion 2018; 18288577: 1652-1654.
24. [24] Valdes NH, Jones KJ, Opila RL, Shafarman WN. Influence of Ga and Ag on the KF treatment chemistry for CIGS solar cells. IEEE Journal of Photovoltaics 2019; 9(6): 1846-1851.
25. [25] Sun Y, Lin S, Li W, Cheng S, Zhang Y, Liu Y, Liu W. Review on alkali element doping in Cu(In,Ga)Se2 thin films and solar cells. Engineering 2017; 3: 452-459.
26. [26] Donzel-Gargand O, Larsson F, Törndahl T, Stolt L, Edoff M. (). Secondary phase formation and surface modification from a high dose KF-post deposition treatment of (Ag,Cu)(In,Ga)Se2 solar cell absorbers. Progress in Photovoltaics: Research and Applications 2018; 27: 220-228.
27. [27] Aboulfadl H, Sopiha KV, Keller J, Larsen JK, Scragg JJS, Persson C, Thuvander M, Edoff M. Alkali dispersion in (Ag,Cu)(In,Ga)Se2 thin film solar cells – Insight from theory and experiment. ACS Applied Materials & Interfaces 2021; 13: 7188-7199.
28. [28] Wei SH, Zhang SB, Zunger A. Effects of Ga addition to CuInSe2 on its electronic, structural, and defect properties. Applied Physics Letters 1998; 72: 3199-3201.
29. [29] Sopiha KV, Larsen JK, Donzel-Gargand O, Khavari F, Keller J, Edoff M, Platzer-Björkman C, Persson C, Scragg JJS. Thermodynamic stability, phase separation and Ag grading in (Ag,Cu)(In,Ga)Se2 solar absorbers. Journal of Materials Chemistry A 2020; 8: 8740-8751.
30. [30] Dullweber TH, Hanna G, Rau U, Schock HW. A new approach to high-efficiency solar cells by band gap grading in Cu(In,Ga)Se2 chalcopyrite semiconductors. Solar Energy Materials & Solar Cells 2001; 67: 145-150.
31. [31] Nwakanma O, Subramaniam V, Morales-Acevedo A. Review on the effects due to alkali metals on copper–indium–gallium–selenide solar cells. Materials Today Energy 2021; 20: 100617.