Computational and experimental characterizations of annealed Cu2ZnSnS4 thin films

Ahmad A Ahmad; A B Migdadi; Ahmad M Alsaad; I A Qattan; Qais M Al-Bataineh; Ahmad Telfah

doi:10.1016/j.heliyon.2021.e08683

Computational and experimental characterizations of annealed Cu₂ZnSnS₄ thin films

Heliyon. 2021 Dec 28;8(1):e08683. doi: 10.1016/j.heliyon.2021.e08683. eCollection 2022 Jan.

Authors

Ahmad A Ahmad¹, A B Migdadi¹, Ahmad M Alsaad¹, I A Qattan², Qais M Al-Bataineh¹, Ahmad Telfah^{3

4}

Affiliations

¹ Department of Physical Sciences, Jordan University of Science & Technology, P.O. Box 3030, Irbid, 22110, Jordan.
² Department of Physics, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
³ Hamdi Mango Center for Scientific Research, (HMCSR), Jordan University, Amman, 11942, Jordan.
⁴ Leibniz Institut für Analytische Wissenschaften-ISAS-e.V., Bunsen-Kirchhoff-Straße 11, 44139 Dortmund, Germany.

Abstract

We report on the synthesis and characterization of Cu₂ZnSnS₄ (CZTS) thin films prepared at different annealing temperatures using the sol-gel method and deposited on glass substrates using the immersing method. The XRD analysis demonstrates that the films annealed at 450 °C exhibit the most stable tetrahedral kesterite structure. Computationally, the Vienna ab initio simulation package (VASP) has been implemented to calculate critical structural properties of as-prepared CZTS) thin films and compared with those extracted from the XRD patterns. An excellent agreement is obtained between the calculated and measured structural parameters. Optical measurement of key optical parameters of annealed CZTS thin films shows a drastic manipulation of all-optical properties compared to the as-prepared thin films. In particular, an optical band gap of 1.62 eV obtained for annealed CZTS thin films at 450 °C makes them eligible to be potential candidates for thin film-based high-efficiency solar cells. Calculations of elastic properties of annealed thin films reveal that crystallite size increases and microstrain decrease compared with those of as-prepared thin films. The sheet resistance of annealed CZTS thin films exhibits a significant decline as the annealing temperature is increased. The electrical properties of annealed CZTS thin films could match some conductors. Remarkably, at 450 °C annealing temperature, the sheet resistance decreases to 74 Ω.cm^-1 indicating the possibility of using the annealed CZTS thin films for efficient and low cost solar cell applications.

Keywords: Cu2ZnSnS4 (CZTS); DFT; Kesterite; Optical properties; Sol-gel; Structural properties; Thin films; VASP; XRD.