硫化物靶与单质靶制备Cu2ZnSnS4薄膜的比较研究

为了验证磁控溅射硫化物靶替代单质靶制备Cu₂ZnSnS₄(CZTS)薄膜及太阳电池的可行性与优越性, 采用多周期磁控溅射ZnS-Sn-CuS和Zn-Sn-Cu制备CZTS薄膜, 并分析了使用不同溅射靶材对薄膜晶体结构、相纯度、表面粗糙度、化学组分、表面、截面形貌及光电特性的影响。按SLG/Mo/CZTS/CdS/i-ZnO/ZnO:Al/Ni-Al结构制成完整的电池器件并测量了J-V曲线。结果显示采用ZnS-Sn-CuS靶制备的CZTS薄膜太阳电池开路电压为611 mV, 短路电流密度为21.28 mA/cm ², 光电转换效率达5.11%; 而以单质靶为基础制备的太阳电池开路电压为594 mV, 短路电流密度为18.56 mA/cm ², 光电转换效率为4.13%。这归因于采用ZnS-Sn-CuS制备的CZTS薄膜相比于单质靶更加平整致密, 纵向生长更好。证明了采用硫化物靶制备CZTS薄膜及太阳电池相较于单质靶的优越性。

Comparative Study of Cu2ZnSnS4 Thin Films Prepared by Chalcogenide and Single Targets

To verify feasibility and superiority of preparing Cu₂ZnSnS₄ (CZTS) thin films and solar cells by sputtering chalcogenide targets instead of single targets, two kinds of CZTS thin films were synthesized via multi-period sputtering ZnS-Sn-CuS and Zn-Sn-Cu, respectively. Influence of different sputtering targets on crystal structure, phase purity, surface roughness, chemical composition, surface and cross-sectional morphology, and optical-electrical properties of CZTS thin films were investigated in detail. Subsequently, the complete devices were fabricated according to SLG/Mo/CZTS/CdS/i-ZnO/ZnO:Al/Ni-Al and J-V characteristics of cells were measured. The results show that the solar cell made of ZnS-Sn-CuS precursor owns an open-circuit voltage of 611 mV, short-circuit current density of 21.28 mA/cm ² and efficiency of 5.11% while the solar cell based on single targets shows an open-circuit voltage of 594 mV, short-circuit current density of 18.56 mA/cm ² and an efficiency of 4.13%. It is attributed to the fact that the CZTS thin films prepared by ZnS-Sn-CuS have smoother, denser surface and better longitudinal growth compared with those prepared by single targets. The result confirms the superiority of the CZTS thin film and solar cells prepared using the chalcogenide targets over those from single targets.