A new route of grow ZnO seed layer using the SILAR method

Abstract

In dye-sensitized solar cells (DSSC), the SnO2 film is used as a transparent conducting electrode. Onto this layer, the n-type semiconductor ZnO is deposited to support the dye. The ZnO/SnO2 interface exhibits electrical resistance due to mis-orientation in the crystalline structures of the two oxides, which is a deleterious factor. In this investigation, the successive ionic layer adsorption reaction (SILAR) method was used to grow the ZnO seed layer with low mis-orientation. In this new process, we used two cationic baths with different compositions. First, the counter-ion Zn(NO)3 solution was used to form the nuclei by adsoption of Zn2+ on the substrate. This was then converted to ZnO by immersion in an anionic bath. Susequently the zinc acetate bath was used for growth. This approach avoids twins parallel to the (0001) plane of the ZnO crystalline structure. The micrographs showed a dense layer and homogeneous petal array, with high orientation in the C axis, which improves electron transport.