直流磁控溅射厚度对Cu(In_x,Ga_(1-x))Se_2背接触Mo薄膜性能的影响

Effect of thickness on the properties of Cu(In_x,Ga_(1-x) )Se_2 back conduct Mo thin films prepared by DC sputtering

采用直流磁控溅射工艺,在一定条件下通过控制溅射时间,在钠钙玻璃上制备了不同厚度的用于Cu(Inx,Ga1-x)Se2薄膜太阳电池背接触材料的Mo薄膜,并利用X射线衍射(XRD)、场发射扫描电子显微镜(SEM)、四探针测试仪、台阶仪研究了厚度对溅射时间、薄膜微结构、电学性能及力学性能的交互影响.Mo薄膜的厚度与溅射时间呈线性递增关系;随厚度的增大,Mo薄膜(110)和(211)面峰强均逐渐增大,择优生长从(110)方向逐渐向(211)方向转变,方块电阻值只随(110)方向上的生长而急剧减小直到一特定值约2/,电导率随薄膜的(110)择优取向程度的降低而线性减小直到一特定值约0.96×10-4Ω·cm;Mo薄膜内部是一种多孔的长形簇状颗粒和颗粒间隙交织的结构,并处于拉应力态,其内部应变随薄膜厚度的增大而减小.

In this study, Mo thin films which used in Cu（Inx Gal-x）Se2 （CIGS） thin film solar cells as back conduct were deposited on soda- lime glass substrates via DC magnetron sputtering under certain conditions. A series of Mo thin films prepared of various thicknesses was obtained in different sputtering deposition times. The microstructure, electrical resistivity and mechanical strain property of Mo thin films, which may be varied by controlling the thickness, were investigated by XRD, SEM, four probes technology and Scotch tape test. As the results showed, the thicknesses of the films increased linearly with the sputtering time. With increasing thickness, the films＇ crystal growth showed a change from （110） preferred orientation to （211） preferred orientation. The sheet resistance sharply reduced to 2 Ω/□ with the increase of （110） peak height and the resistivity linearly decreased to 0.96 × 10^-4 12.cm due to the level of （110） preferred orientation. The films surface has porous （fish-like） grain morphology and intergranular voids. All the films are in a tensile state, and the inner strain decreased with the increase of the thickness.