Synthesis and Characterization of CZTS Thin Films by Sol-Gel Method without Sulfurization

One process of layer-by-layer sol-gel deposition without sulfurization was developed. The CZTS films with 1.2 μm and the sulfur ratio of ~48% were prepared and their characteristics were measured. The as-deposited and annealed films are of Kesterite structure. The as-deposited films do not present obvious electric conduction type. However, the annealed 9-LAY-ANN film is p-type conduction and has sheet resistance of 4.08 kΩ/□ and resistivity of 4.896 × 10−1 Ω·cm. The optic energy gap is 1.50 eV for as-deposited films and is 1.46 eV after being annealed. The region deposited by using Lo-Con solution is more compact than that by the Hi-Con solution from SEM morphology images.