The invention discloses a composite back reflection
metal electrode for a
thin film solar cell; the composite back reflective
metal electrode is a composite multi-layer film, and a
transition layer metal, a
silver film and aluminum-doped
zinc oxide are sequentially deposited on a substrate. The invention further discloses a preparation method of the composite back reflective metal
electrode. According to the composite back reflective metal electrode disclosed by the invention, as the
transition layer metal has excellent adhesion with the flexible substrate, all
layers of the deposited thin films are less prone to shed from the substrate; simultaneously, the
silver film has obvious texture, and a light
trapping structure is formed, so that the reflection of incident light is enhanced, the absorption of the incident light in an
absorption layer of the
cell is fuller, and the performances of the
cell can be improved; and the aluminum-doped
zinc oxide has appropriate thickness, so that the aluminum-doped
zinc oxide can not only prevent silver from being diffused and entering into the
cell during the preparation process of the cell, but also have the effects of covering a peak on the surface of the
silver film and enhancing reflected light. Therefore, the composite back reflective metal electrode disclosed by the invention can improve the bonding force between the thin films and the substrate, and significantly improve the performances of the cell and the uniformity.