摘要
在含有ZnSO4,SC(NH2)2,NH4OH的水溶液中采用CBD法沉积ZnS薄膜,XRF和热处理前后的XRD测试表明,ZnS沉积薄膜为立方相结构,薄膜含有非晶态的Zn(OH)2.光学透射谱测试表明,制备的薄膜透过率(λ>500nm)约为90%,薄膜的禁带宽度约为3·51eV.ZnS薄膜沉积时间对Cu(In,Ga)Se2太阳电池影响显著,当薄膜沉积时间在25～35min时,电池的综合性能最好.对比了不同缓冲层的电池性能,采用CBD-CdS为缓冲层的电池转换效率、填充因子、开路电压稍高于CBD-ZnS为缓冲层的无镉电池,但无镉电池的短路电流密度高于前者,两者转换效率相差2%左右.ZnS可以作为CIGS电池的缓冲层,替代CdS,实现电池的无镉化.
We report the deposition and structural characterization of zinc sulfide （ZnS） thin films by chemical bath deposition （CBD） from a bath containing thiourea, ZnSO4, and ammonia in aqueous solution. The XRF and XRD analysis of as-deposited and annealed films show that the films have cubic ZnS structure with Zn（OH）2. Transmission measurements show that the optical transmittance is about 90% when the wavelength is over 500nm. The band gap （Eg） value of the deposited film is about 3. 51eV. The effect of the ZnS buffer layer deposition time on device performance is studied. The result shows that the cell performance with a CBD-ZnS buffer layer deposited for 25-35min is best. The performance of CIGS solar cells with different buffer layers is compared. These results suggest that CBD-ZnS thin film can alternate CBD-CdS thin film as the buffer layer of CIGS solar cells.
基金
国家高技术研究发展计划(批准号:2004AA513021)
安徽省高等学校青年教师科研基金(批准号:2006jq1151)
安徽省教育厅自然科学基金(批准号:KJ2007B062)资助项目~~
