Fabrication of Three-Dimensional-Structure Solar Cell with Cu_2ZnSnS_4

摘要

We fabricated three-dimensional (3D)-structure solar cells with Cu_2ZnSnS_4 (CZTS). A CdS buffer layer was deposited around nc-TiO_2 by the chemical bath deposition (CBD) method. The CdS deposition time was varied from 5 to 30 min at 65 ℃. CZTS absorber was deposited by spray pyrolysis deposition (SPD) onto the CdS buffer layer. Cu-, Zn-, Sn-, and S-containing solutions were used in SPD. The metal sources of copper( Ⅱ) acetate monohydrate, zinc( Ⅱ) acetate dehydrate, and tin( Ⅱ) chloride dehydrate, and pure sulfur powder were desolved in N,N-dimethylformamide (DMF) as a solvent and mono-ethanolamine as a stabilizer. The solution-sprayed 3D-structure substrate was annealed in a nitrogen atmosphere at 250 ℃ for 30 min. A 3D-structure CZTS solar cell presented the best conversion efficiency η of 0.51 % with a CdS buffer layer deposition time of 20 min. The dependence of each solar cell characteristic on CdS buffer layer deposition time was measured.