Impact of Annealing on Structural, Optical, and Electrical Characteristics of Spin Coated Cu2ZnSnS4 Thin Films

Cu2ZnSnS4 (CZTS) thin films were deposited on glass slides using the spin coating technique. The fabricated samples were then subjected to annealing at 250, 300, and 350 degrees C temperatures, and their structural, optical, and electrical characteristics were then examined. X-ray diffraction and Raman analysis demonstrated the development of kesterite, and single-phase CZTS thin films at all the annealing temperatures, respectively. Optical characteristics of annealed thin films were studied. Depending upon the annealing temperature, the band gap value of the annealed films varies from 1.5 to 1.9 eV. Hall measurements revealed the p-type semiconducting behavior of the annealed thin films. Also, the hall mobility and conductivity of the thin films increase with annealing temperature. The current-voltage (I-V) curves for annealed samples are almost linear whose slope (I/V) increases with annealing temperature. Thus, the resistivity of the thin films decreases with annealing temperature, which verifies the semiconducting behavior of the CZTS thin films.