连续离子层吸附反应沉积后硫化法制备柔性铜锌锡硫薄膜太阳电池

在柔性钼箔衬底上采用连续离子层吸附反应法(successive ionic layer absorption and reaction)制备ZnS/Cu2SnSx叠层结构的预制层薄膜,预制层薄膜在蒸发硫气氛、550 C温度条件下进行退火得到Cu2ZnSnS4吸收层.分别采用EDS,XRD,Raman,SEM表征吸收层薄膜的成分、物相和表面形貌.结果表明,退火后薄膜结晶质量良好,表面形貌致密.用在普通钠钙玻璃上采用相同工艺制备的CZTS薄膜表征薄膜的光学和电学性能,表明退火后薄膜带隙宽度为1.49 eV,在可见光区光吸收系数大于104cm 1,载流子浓度与电阻率均满足薄膜太阳电池器件对吸收层的要求.用上述柔性衬底上的吸收层制备Mo foil/CZTS/CdS/i-ZnO/ZnO:Al/Ag结构的薄膜太阳电池得到2.42%的效率,是目前报道柔性CZTS太阳电池最高效率.

Fabrication of flexible Cu2ZnSnS4 (CZTS) solar cells by sulfurizing precursor films deposited via successive ionic layer absorption and reaction method

Cu₂ZnSnS₄ (CZTS) precursor thin films were prepared on a flexible Mo foil substrate via ZnS/Cu₂SnS_x stacked structure using successive ionic layer absorption and reaction (SILAR) method; the precursor thin films were annealed at 550 ℃ in sulfur atmosphere to obtain CZTS absorber layers. The chemical composition,crystallinity and surface morphology were characterized by EDS, XRD, Raman and SEM, respectively, indicating that the annealed films are highly crystallin and have compact morphology. In order to analyse the optical and electrical properties of the films, same processes were implemented on the soda glasses. Results reveal that the band gaps of the annealed films are 1.49 eV, the absorption coefficients are higher than 10⁴ cm^-1, and the carrier concentration as well as the electrical resistivity is suitable for fabrication of thin film solar cells. Flexible solar cells with a structure of Mo foil/CZTS/CdS/i-ZnO/ZnO: Al/Ag were fabricated by the above CZTS absorber layers, which demonstrated an efficiency of, 2.42%, the record efficiency of flexible CZTS solar cells as far as we know.