CdTe太阳电池前电极SnO2:F/SnO2复合薄膜性能分析

减薄CdS窗口层是提高CdS/CdTe太阳电池转换效率的有效途径之一,减薄窗口层会对器件造成不利的影响,因此在减薄了的窗口层与前电极之间引入过渡层非常必要.利用反应磁控溅射法在前电极SnO₂:F薄膜衬底上制备未掺杂的SnO₂薄膜形成过渡层,并将其在N₂/O₂=4 ∶1,550 ℃环境进行了30 min热处理,利用原子力显微镜、X射线衍射仪、紫外分光光度计对复合薄膜热处理前后的形貌、结构、光学性能进行了表征,同时分析了复

Performance of SnO2:F/SnO2 composite film as front-electrode for CdTe solar cells

Decreasing CdS thickness is one of the effective ways to improve the conversion efficiency of CdS/CdTe solar cells. In order to eliminate the adverse effects of the decrease in CdS thickness on the performances of the devices, it is necessary to introduce a buffer layer between CdS and front electrode layer. The un-doped SnO₂thin films, as a buffer layer, were deposited on SnO₂:F thin film by magnetic reactive sputtering. Then the composite film was annealed at 550 ℃ in N₂/O₂=4 ∶1 ambience for 30 minutes. The morphology, structure and optical properties of the composite film before and after annealing were studied by AFM, XRD, UV-Vis and the electrical properties were analyzed, respectively. As a result, the crystal lattice parameters of un-doped SnO₂ films matched those of the substrate, so the un-doped SnO₂ films, which had an obvious preferred orientation along (110) plan, had the same structure as the substrate materials. This implied that there was no lattice mismatch. After annealing, the surface topography and electricity uniformity were improved, higher than 80% transparency was obtained, and resistance increased to meet the requirements of the buffer layers. Finally, continuous and homogeneous SnO₂:F/ SnO₂ composite thin films have been obtained, which were very suitable for CdS/CdTe cells.